Wireless power transfer method, wireless power transmitter and wireless charging system

ABSTRACT

The present disclosure relates to a wireless power transfer method, a wireless power transmitter and a wireless charging system in a wireless power transfer field. That is, a wireless power transmitter configured to transfer power to a wireless power receiver in a wireless manner includes a power transfer unit configured to transmit power to the wireless power receiver in the wireless manner, a circuit unit having a plurality of capacitors electrically connected to the power transfer unit, and configured to support each of a plurality of frequencies by changing the electric connection of the capacitors, and a controller configured to detect a communication standard that the wireless power receiver supports, and control the electric connection of the capacitors such that the circuit unit operates at a frequency corresponding to the detected communication standard.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. §119(a), this application claims the benefit ofearlier filing date and right of priority to U.S. provisionalApplication Nos. 61/830,466, 61/835,639 and 61/924,242 filed on Jun. 3,2013, Jun. 17, 2013 and Jan. 7, 2014, and Korean Application Nos.10-2014-0054985, 10-2014-0060541, 10-2014-0066331 filed on May 8, 2014,May 20, 2014, May 30, 2014, the contents of which are incorporated byreference herein in their entireties.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

This specification relates to a wireless power transfer method,apparatus, and system in a wireless power transfer field.

2. Background of the Disclosure

In recent years, the method of contactlessly supplying electrical energyto wireless power receivers in a wireless manner has been used insteadof the traditional method of supplying electrical energy in a wiredmanner. The wireless power receiver receiving energy in a wirelessmanner may be directly driven by the received wireless power, or abattery may be charged by using the received wireless power, thenallowing the wireless power receiver to be driven by the charged power.

For allowing smooth wireless power transfer between a wireless powertransmitter which transmits power in a wireless manner and a wirelesspower receiver which receives power in a wireless manner, thestandardization for a technology related to the wireless power transferis undergoing.

As part of the standardization for the wireless power transfertechnology, the Wireless Power Consortium (WPC) which managestechnologies for a magnetic inductive wireless power transfer haspublished a standard document “System description Wireless PowerTransfer, Volume 1, Low Power, Part 1: Interface Definition, Version1.00 Release Candidate 1 (RC1)” for interoperability in the wirelesspower transfer on Apr. 12, 2010.

Power Matters Alliance as another technology standardization consortiumhas been established on March, 2012, developed a product line ofinterface standards, and published a standard document based on aninductive coupling technology for providing inductive and resonantpower.

A wireless charging method using electromagnetic induction is frequentlyencountered in our lives, for example, is utilized by beingcommercialized in electric toothbrushes, wireless coffee ports and thelike.

WPC1.1 standard and PMA1.1 standard have been published, but they haveproblems that a receiver has to be correctly arranged on a charging coiland interoperability between the standards is not good. Therefore, it isrequired to develop a transmitter having interoperability betweenwireless charging standards.

SUMMARY OF THE DISCLOSURE

Therefore, an aspect of the detailed description is to provide awireless power transfer method, a wireless power transmitter and awireless charging system, capable of providing interoperability betweena WPC standard and a PMA standard.

Another aspect of the detailed description is to provide a new type ofmulti-coil solution, capable of extending a degree of position freedomof receivers by an assembly of single coils compliant with differentstandards in a wireless charging field.

One aspect of the detailed description is to provide a wireless powertransfer method, a wireless power transmitter and a wireless chargingsystem, capable of providing interoperability between a WPC standard anda PMA standard. To this end, a wireless power transmitter configured totransfer power to a wireless power receiver in a wireless manner mayinclude a first coil configured to convert a current into a magneticflux, a second coil configured to be adjacent to the first coil on aplane, a third coil configured to have a different shape from the firstand second coils and have at least part thereof which overlaps the firstand second coils, respectively, and a controller configured to determinea coil to be activated among the first, second and third coils.

In accordance with one exemplary embodiment disclosed herein, thecontroller may selectively apply one of a plurality of voltages to thethird coil.

In accordance with one exemplary embodiment disclosed herein, thecontroller may control a driving circuit unit. The driving circuit unitmay include a first switch connected to a first capacitor, and a secondswitch connected to a second capacitor. The first capacitor and thesecond capacitor may be connected to the third coil in parallel.

In accordance with one exemplary embodiment disclosed herein, the firstand second switches may be controlled to apply the one of the pluralityof voltages to the third coil according to whether the standardcorresponds to a first standard or a second standard, different fromeach other.

In accordance with one exemplary embodiment disclosed herein, Thecontroller may apply an input voltage to at least one of the first,second and third coils, and after detection of the standard, may boostor depressurize the input voltage to correspond to the standard.

In accordance with one exemplary embodiment disclosed herein, thecontroller may determine which one of the first, second and third coilsis to be controlled when the standard is the first standard, and carryout a frequency control by boosting the input voltage applied to thethird coil when the standard is the second standard.

In accordance with one exemplary embodiment disclosed herein, the firstand second coils may be coils to which the input voltage is applied incompliance with the first standard, and the third coil may be set suchthat a voltage higher than the input voltage is applied thereto.

In accordance with one exemplary embodiment disclosed herein, the firstand second coils may be coils for which a frequency control or a voltagecontrol is carried out in compliance with the first standard, and thethird coil may be a coil for which the voltage control is carried out incompliance with the first standard.

In accordance with one exemplary embodiment disclosed herein, the firstand second coils may be wound into a quadrilateral shape in which atleast part is straight (linear), and the third coil may be wound into acircular shape.

In accordance with one exemplary embodiment disclosed herein, the firstand second coils may consist of a single layer, and the third coil mayconsist of a plurality of layers in a manner that the coil is connectedat an inner side thereof and wounded into a plurality of layers.

In accordance with one exemplary embodiment disclosed herein, the thirdcoil may be a coil which complies with both the first standard and thesecond standard, and the first and second coils may be coils compliantwith the first standard.

A wireless power transfer method, which is configured to transfer powerto a wireless power receiver in a wireless manner in accordance with oneexemplary embodiment disclosed herein, may include applying an inputvoltage to at least one of first, second, and third coils, detecting astandard applied to the wireless power receiver to correspond to theinput voltage, and detecting a coil to be driven from the first, secondand third coils when the standard Is a first standard, and driving thethird coil when the standard is a second standard.

In accordance with one exemplary embodiment disclosed herein, thedetecting of the coil to be driven may be carried out to detect whethera coil to be driven is a coil wound into a quadrilateral shape or a coilwound into a circular shape when the standard is the first standard.

In accordance with one exemplary embodiment disclosed herein, the inputvoltage may be boosted when the coil to be driven is the coil wound intothe circular shape, and the input voltage may be maintained when thecoil to be driven is a coil wound into a quadrilateral shape.

In accordance with one exemplary embodiment disclosed herein, the inputvoltage may be boosted and a frequency control may be carried out whenthe standard is the second standard.

A wireless charging system in accordance with one exemplary embodimentdisclosed herein may include a transmitter configured to transfer powerin a wireless manner, and a receiver configured to receive power in awireless manner, wherein the transmitter may include a first coilconfigured to convert a current into a magnetic flux, a second coilconfigured to be adjacent to the first coil on a plane, a third coilconfigured to have a different shape from the first and second coils andhave at least part thereof which overlaps the first and second coils,respectively, and a controller configured to determine a coil to beactivated among the first, second and third coils.

In accordance with one exemplary embodiment disclosed herein, thecontroller may selectively apply one of a plurality of voltages to thethird coil.

In accordance with one exemplary embodiment disclosed herein, thecontroller may apply an input voltage to at least one of the first,second and third coils, and after detection of the standard, may boostor depressurize the input voltage to correspond to the standard.

In accordance with one exemplary embodiment disclosed herein, the firstand second coils may be wound into a quadrilateral shape in which atleast part is straight (linear), and the third coil may be wound into acircular shape.

A wireless power transmitter, which is configured to transfer power to awireless power receiver in a wireless manner, in accordance with anotherexemplary embodiment disclosed herein may include a power transfer unitconfigured to transmit power to the wireless power receiver in thewireless manner, a circuit unit having a plurality of capacitorselectrically connected to the power transfer unit, and configured tosupport each of a plurality of frequencies by changing the electricconnection of the capacitors, and a controller configured to detect acommunication standard that the wireless power receiver supports, andcontrol the electric connection of the capacitors such that the circuitunit operates at a frequency corresponding to the detected communicationstandard.

In accordance with one exemplary embodiment disclosed herein, thecircuit unit may vary the number of capacitors included in a resonantcircuit for transmitting power in the wireless manner among theplurality of capacitors.

In accordance with one exemplary embodiment disclosed herein, thecircuit unit may include a first capacitor electrically connected to thepower transfer unit, a second capacitor connected to the first capacitorin parallel, and a switch connected to the second capacitor. Thecontroller may control the electric connection of the second capacitorusing the switch.

In accordance with one exemplary embodiment disclosed herein, thecontroller may turn on the switch when the detected communicationstandard is a Wireless Power Consortium (WPC) communication standard,and turns off the switch when the detected communication standard is aPower Matters Alliance (PMA) communication standard.

In accordance with one exemplary embodiment disclosed herein, thecontroller may generate signals complying with different communicationstandards in a sequential manner, to detect a communication standardthat the wireless power receiver supports.

In accordance with one exemplary embodiment disclosed herein, thesignals may include a first signal complying with a first communicationstandard, and a second signal complying with a second communicationstandard. The controller may decide whether the wireless power receiversupports the first communication standard or the second communicationstandard using a response of the wireless power receiver to one of thefirst and second signals.

In accordance with one exemplary embodiment disclosed herein, thecontroller may control the electric connection of the plurality ofcapacitors such that the circuit unit operates in a frequency rangecorresponding to the decided one communication standard when the onecommunication standard is decided.

In accordance with one exemplary embodiment disclosed herein, thecontroller may boost or depressurize an input voltage such that thecircuit unit can support the decided one communication standard when theone communication standard is decided.

In accordance with one exemplary embodiment disclosed herein, thecontroller may carry out one of a frequency control and a voltagecontrol with respect to the power transfer unit based on the decided onecommunication standard when the one communication standard is decided.

In accordance with one exemplary embodiment disclosed herein, thecircuit unit may include a first switch connected to a first capacitor,and a second switch connected to a second capacitor. The first capacitorand the second capacitor may be connected in parallel, and thecontroller may control an electric connection of the second capacitorusing the first and second switches.

In accordance with one exemplary embodiment disclosed herein, thecontroller may control the first and second switches such that both ofthe first and second capacitors are electrically connected to the powertransfer unit when the communication standard complies with the WPC, andcontrol the first and second switches such that one of the first andsecond capacitors is electrically connected to the power transfer unitwhen the communication standard complies with the PMA.

In accordance with one exemplary embodiment disclosed herein, the powertransfer unit may be a WPC-compliant A13 coil for which a frequencycontrol or a voltage control is carried out.

A wireless power transfer method, which is configured to transmit powerto a wireless power receiver in a wireless manner, in accordance withone exemplary embodiment disclosed herein may include generating a firstsignal complying with a first communication standard and a second signalcomplying with a second communication standard in a sequential manner,so as to detect a communication standard that the wireless powerreceiver supports, determining a communication standard that thewireless power receiver supports from the first and second communicationstandards, using a response of the receiver to one of the first andsecond signals, and controlling an electric connection of a plurality ofcapacitors such that power is transferred in the wireless manner at oneof a plurality of frequency bands according to the determinedcommunication standard.

In accordance with one exemplary embodiment disclosed herein, thecontrolling of the electric connection of the capacitors may beperformed to decide the number of capacitors to be used in a resonantcircuit compliant with the determined communication standard.

In accordance with one exemplary embodiment disclosed herein, a firstcapacitor and a second capacitor may be provided. A switch may beconnected to the second capacitor. The controlling of the electricconnection of the capacitors may be performed to turn on the switch whenthe determined communication standard is the WPC communication standard.

In accordance with one exemplary embodiment disclosed herein, the methodmay further include boosting or depressurizing an input voltageaccording to the determined communication standard.

A wireless charging system in accordance with one exemplary embodimentdisclosed herein may Include a transmitter configured to transmit powerin a wireless manner, and a receiver configured to receive power fromthe transmitter in a wireless manner. Here, the transmitter may includea power transfer unit configured to transmit power to the receiver inthe wireless manner, a circuit unit having a plurality of capacitorselectrically connected to the power transfer unit, and configured tosupport each of a plurality of frequencies by changing the electricconnection of the capacitors, and a controller configured to detect acommunication standard that the wireless power receiver supports, andcontrol the electric connection of the capacitors such that the circuitunit operates at a frequency corresponding to the detected communicationstandard.

In accordance with one exemplary embodiment disclosed herein, the powertransfer unit may be configured as a WPC-compliant A13 coil. Thecontroller may decide the number of capacitors to be included in aresonant circuit compliant with the communication standard which thereceiver complies with.

In accordance with one exemplary embodiment disclosed herein, thecircuit unit may further include a switch connected to at least part ofthe plurality of capacitors, and the controller may decide a capacitorto be used in the resonant circuit using the switch.

In accordance with one exemplary embodiment disclosed herein, thecontroller may generate signals complying with different communicationstandards in a sequential manner so as to detect the standard that thereceiver supports.

Further scope of applicability of the present application will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating preferred embodiments of the disclosure, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the disclosure will becomeapparent to those skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments andtogether with the description serve to explain the principles of thedisclosure.

In the drawings:

FIG. 1 is an exemplary view conceptually illustrating a wireless powertransmitter and a wireless power receiver according to the embodimentsof the present invention;

FIGS. 2A and 2B are exemplary block diagrams illustrating theconfiguration of a wireless power transmitter and a wireless powerreceiver that can be employed in the embodiments disclosed herein,respectively;

FIG. 3 is a view illustrating a concept in which power is transferredfrom a wireless power transmitter to a wireless power receiver in awireless manner according to an inductive coupling method;

FIGS. 4A and 4B are a block diagram illustrating part of the wirelesspower transmitter and wireless power receiver in a magnetic Inductionmethod that can be employed in the embodiments disclosed herein;

FIG. 5 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmitting coils receiving poweraccording to an inductive coupling method that can be employed in theembodiments disclosed herein;

FIG. 6 is a view illustrating a concept in which power is transferred toa wireless power receiver from a wireless power transmitter in awireless manner according to a resonance coupling method;

FIGS. 7A and 7B are a block diagram illustrating part of the wirelesspower transmitter and wireless power receiver in a resonance method thatcan be employed in the embodiments disclosed herein;

FIG. 8 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmitting coils receiving poweraccording to a resonance coupling method that can be employed in theembodiments disclosed herein;

FIG. 9 a view illustrating a concept of transmitting and receiving apacket between a wireless power transmitter and an electronic devicethrough the modulation and demodulation of a wireless power signal intransferring power in a wireless manner disclosed herein;

FIG. 10 is a view illustrating a configuration of transmitting andreceiving a power control message in transferring power in a wirelessmanner disclosed herein;

FIG. 11 is a view illustrating forms of signals upon modulation anddemodulation executed in a wireless power transfer disclosed herein;

FIG. 12 is a view illustrating a packet including a power controlmessage used in a contactless (wireless) power transfer method accordingto the embodiments disclosed herein;

FIG. 13 is a view illustrating operation phases of the wireless powertransmitter and wireless power receiver according to the embodimentsdisclosed herein;

FIGS. 14 to 18 are views illustrating the structure of packets includinga power control message between the wireless power transmitter 100 andthe wireless power receiver,

FIG. 19 is a conceptual view illustrating a method of transferring powerto at least one wireless power receiver from a wireless powertransmitter;

FIGS. 20 and 21 are a planar view and a front view respectivelyillustrating a transmission unit of a transmitter with an assembly ofsingle coils;

FIGS. 22A and 22B are a planar view and a front view of a first typecoil illustrated in FIG. 20;

FIGS. 23A and 23B are a planar view and a front view of a second typecoil illustrated in FIG. 20;

FIGS. 24A and 24B are front views illustrating an exemplary variation ofthe transmitter of FIG. 21;

FIG. 25 is a flowchart illustrating a method for driving (operating) atransmitter;

FIG. 26 is a detailed flowchart Illustrating one embodiment of theoperating method of FIG. 25;

FIG. 27 is a structural view of a circuit implementing the operatingmethod of FIG. 26;

FIGS. 28 and 29 are a block diagram of a wireless power transmitter, anda flowchart illustrating a method of operating the transmitter totransmit power in a wireless manner to a receiver supporting twodifferent standards;

FIG. 30 is a conceptual view illustrating a coil useable in a wirelesspower transmitter;

FIG. 31 is a structural view of a circuit implementing a method ofwirelessly transferring power in a wireless power transmitter to becompliant with different standards;

FIG. 32 is a graph illustrating test results as to whether a wirelesspower transmitter supports communication compliant with two differentstandards;

FIG. 33 is a flowchart illustrating a method of detecting acommunication standard in a wireless power transmitter;

FIG. 34 is a graph illustrating test results according to FIG. 33; and

FIG. 35 is a circuitry view illustrating another method of constructinga circuitry view of a wireless power transmitter.

DETAILED DESCRIPTION OF THE DISCLOSURE

The technologies disclosed herein may be applicable to wireless powertransfer (contactless power transfer). However, the technologiesdisclosed herein are not limited to this, and may be also applicable toall kinds of power transmission systems and methods, wireless chargingcircuits and methods to which the technological spirit of the technologycan be applicable, in addition to the methods and apparatuses usingpower transmitted in a wireless manner.

It should be noted that technological terms used herein are merely usedto describe a specific embodiment, but not to limit the presentinvention. Also, unless particularly defined otherwise, technologicalterms used herein should be construed as a meaning that is generallyunderstood by those having ordinary skill in the art to which theinvention pertains, and should not be construed too broadly or toonarrowly. Furthermore, if technological terms used herein are wrongterms unable to correctly express the spirit of the invention, then theyshould be replaced by technological terms that are properly understoodby those skilled in the art. In addition, general terms used in thisinvention should be construed based on the definition of dictionary, orthe context, and should not be construed too broadly or too narrowly.

Incidentally, unless clearly used otherwise, expressions in the singularnumber include a plural meaning. In this application, the terms“comprising” and “including” should not be construed to necessarilyinclude all of the elements or steps disclosed herein, and should beconstrued not to include some of the elements or steps thereof, orshould be construed to further include additional elements or steps.

In addition, a suffix “module” or “unit” used for constituent elementsdisclosed in the following description is merely intended for easydescription of the specification, and the suffix itself does not giveany special meaning or function.

Furthermore, the terms including an ordinal number such as first,second, etc. can be used to describe various elements, but the elementsshould not be limited by those terms. The terms are used merely for thepurpose to distinguish an element from the other element. For example, afirst element may be named to a second element, and similarly, a secondelement may be named to a first element without departing from the scopeof right of the invention.

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings, and thesame or similar elements are designated with the same numeral referencesregardless of the numerals in the drawings and their redundantdescription will be omitted.

In describing the present invention, moreover, the detailed descriptionwill be omitted when a specific description for publicly knowntechnologies to which the invention pertains is judged to obscure thegist of the present invention. Also, it should be noted that theaccompanying drawings are merely illustrated to easily explain thespirit of the invention, and therefore, they should not be construed tolimit the spirit of the invention by the accompanying drawings.

DEFINITION

Many-to-one communication: communicating between one transmitter (Tx)and many receivers (Rx)

Unidirectional communication: transmitting a required message only froma receiver to a transmitter

Here, the transmitter and the receiver indicate the same as atransmitting unit (device) and a receiving unit (device), respectively.Hereinafter, those terms may be used together.

FIG. 1—Conceptual View of Wireless Power Transmitter and Wireless PowerReceiver

FIG. 1 is an exemplary view conceptually illustrating a wireless powertransmitter and a wireless power receiver according to the embodimentsof the present invention.

Referring to FIG. 1, the wireless power transmitter 100 may be a powertransfer apparatus configured to transfer power required for thewireless power receiver 200 in a wireless manner.

Furthermore, the wireless power transmitter 100 may be a wirelesscharging apparatus configured to charge a battery of the wireless powerreceiver 200 by transferring power in a wireless manner. A case wherethe wireless power transmitter 100 is a wireless charging apparatus willbe described later with reference to FIG. 9.

Additionally, the wireless power transmitter 100 may be implemented withvarious forms of apparatuses transferring power to the wireless powerreceiver 200 requiring power in a contactless state.

The wireless power receiver 200 is a device that is operable byreceiving power from the wireless power transmitter 100 in a wirelessmanner. Furthermore, the wireless power receiver 200 may charge abattery using the received wireless power.

On the other hand, an electronic device for receiving power in awireless manner as described herein should be construed broadly toinclude a portable phone, a cellular phone, a smart phone, a personaldigital assistant (PDA), a portable multimedia player (PMP), a tablet, amultimedia device, or the like, in addition to an input/output devicesuch as a keyboard, a mouse, an audio-visual auxiliary device, and thelike.

The wireless power receiver 200, as described later, may be a mobilecommunication terminal (for example, a portable phone, a cellular phone,and a tablet and the like) or a multimedia device.

On the other hand, the wireless power transmitter 100 may transfer powerin a wireless manner without mutual contact to the wireless powerreceiver 200 using one or more wireless power transfer methods. In otherwords, the wireless power transmitter 100 may transfer power using atleast one of an inductive coupling method based on magnetic inductionphenomenon by the wireless power signal and a magnetic resonancecoupling method based on electromagnetic resonance phenomenon by awireless power signal at a specific frequency.

Wireless power transfer in the inductive coupling method is a technologytransferring power in a wireless manner using a primary coil and asecondary coil, and refers to the transmission of power by inducing acurrent from a coil to another coil through a changing magnetic field bya magnetic induction phenomenon.

Wireless power transfer in the inductive coupling method refers to atechnology in which the wireless power receiver 200 generates resonanceby a wireless power signal transmitted from the wireless powertransmitter 100 to transfer power from the wireless power transmitter100 to the wireless power receiver 200 by the resonance phenomenon.

Hereinafter, the wireless power transmitter 100 and wireless powerreceiver 200 according to the embodiments disclosed herein will bedescribed in detail. In assigning reference numerals to the constituentelements in each of the following drawings, the same reference numeralswill be used for the same constituent elements even though they areshown in a different drawing.

FIGS. 2A and 2B are exemplary block diagrams Illustrating theconfiguration of a wireless power transmitter 100 and a wireless powerreceiver 200 that can be employed in the embodiments disclosed herein.

Wireless Power Transmitter

Referring to FIG. 2A, the wireless power transmitter 100 may include apower transmission unit 110. The power transmission unit 110 may includea power conversion unit 111 and a power transmission control unit 112.

The power conversion unit 111 transfers power supplied from atransmission side power supply unit 190 to the wireless power receiver200 by converting it into a wireless power signal. The wireless powersignal transferred by the power conversion unit 111 is generated in theform of a magnetic field or electro-magnetic field having an oscillationcharacteristic. For this purpose, the power conversion unit 111 may beconfigured to include a coil for generating the wireless power signal.

The power conversion unit 111 may include a constituent element forgenerating a different type of wireless power signal according to eachpower transfer method. For example, the power conversion unit 111 mayinclude a primary coil for forming a changing magnetic field to induce acurrent to a secondary coil of the wireless power receiver 200.Furthermore, the power conversion unit 111 may include a coil (orantenna) for forming a magnetic field having a specific resonantfrequency to generate a resonant frequency in the wireless powerreceiver 200 according to the resonance coupling method.

Furthermore, the power conversion unit 111 may transfer power using atleast one of the foregoing inductive coupling method and the resonancecoupling method.

Among the constituent elements included in the power conversion unit111, those for the inductive coupling method will be described laterwith reference to FIGS. 4 and 5, and those for the resonance couplingmethod will be described with reference to FIGS. 7 and 8.

On the other hand, the power conversion unit 111 may further include acircuit for controlling the characteristics of a used frequency, anapplied voltage, an applied current or the like to form the wirelesspower signal.

The power transmission control unit 112 controls each of the constituentelements included in the power transmission unit 110 The powertransmission control unit 112 may be implemented to be integrated intoanother control unit (not shown) for controlling the wireless powertransmitter 100.

On the other hand, a region to which the wireless power signal can beapproached may be divided into two types. First, an active area denotesa region through which a wireless power signal transferring power to thewireless power receiver 200 is passed. Next, a semi-active area denotesan interest region in which the wireless power transmitter 100 candetect the existence of the wireless power receiver 200. Here, the powertransmission control unit 112 may detect whether the wireless powerreceiver 200 is placed in the active area or detection area or removedfrom the area. Specifically, the power transmission control unit 112 maydetect whether or not the wireless power receiver 200 is placed in theactive area or detection area using a wireless power signal formed fromthe power conversion unit 111 or a sensor separately provided therein.For instance, the power transmission control unit 112 may detect thepresence of the wireless power receiver 200 by monitoring whether or notthe characteristic of power for forming the wireless power signal ischanged by the wireless power signal, which is affected by the wirelesspower receiver 200 existing in the detection area. However, the activearea and detection area may vary according to the wireless powertransfer method such as an inductive coupling method, a resonancecoupling method, and the like.

The power transmission control unit 112 may perform the process ofidentifying the wireless power receiver 200 or determine whether tostart wireless power transfer according to a result of detecting theexistence of the wireless power receiver 200.

Furthermore, the power transmission control unit 112 may determine atleast one characteristic of a frequency, a voltage, and a current of thepower conversion unit 111 for forming the wireless power signal. Thedetermination of the characteristic may be carried out by a condition atthe side of the wireless power transmitter 100 or a condition at theside of the wireless power receiver 200.

The power transmission control unit 112 may receive a power controlmessage from the wireless power receiver 200. The power transmissioncontrol unit 112 may determine at least one characteristic of afrequency, a voltage and a current of the power conversion unit 111based on the received power control message, and additionally performother control operations based on the power control message.

For example, the power transmission control unit 112 may determine atleast one characteristic of a frequency, a voltage and a current used toform the wireless power signal according to the power control messageincluding at least one of rectified power amount information, chargingstate information and identification information in the wireless powerreceiver 200.

Furthermore, as another control operation using the power controlmessage, the wireless power transmitter 100 may perform a typicalcontrol operation associated with wireless power transfer based on thepower control message. For example, the wireless power transmitter 100may receive Information associated with the wireless power receiver 200to be auditorily or visually outputted through the power controlmessage, or receive information required for authentication betweendevices.

In exemplary embodiments, the power transmission control unit 112 mayreceive the power control message through the wireless power signal. Inother exemplary embodiment, the power transmission control unit 112 mayreceive the power control message through a method for receiving userdata.

In order to receive the foregoing power control message, the wirelesspower transmitter 100 may further include a modulation/demodulation unit113 electrically connected to the power conversion unit 111. Themodulation/demodulation unit 113 may modulate a wireless power signalthat has been modulated by the wireless power receiver 200 and use it toreceive the power control message.

In addition, the power transmission control unit 112 may acquire a powercontrol message by receiving user data including a power control messageby a communication means (not shown) included in the wireless powertransmitter 100.

[for Supporting in-Band Two-Way Communication]

Under a wireless power transfer environment allowing for bi-directionalcommunications according to the exemplary embodiments disclosed herein,the power transmission control unit 112 may transmit data to thewireless power receiver 200. The data transmitted by the powertransmission control unit 112 may be transmitted to request the wirelesspower receiver 200 to send the power control message.

Wireless Power Receiver

Referring to FIG. 2B, the wireless power receiver 200 may include apower supply unit 290. The power supply unit 290 supplies power requiredfor the operation of the wireless power receiver 200. The power supplyunit 290 may include a power receiving unit 291 and a power receptioncontrol unit 292.

The power receiving unit 291 receives power transferred from thewireless power transmitter 100 in a wireless manner.

The power receiving unit 291 may include constituent elements requiredto receive the wireless power signal according to a wireless powertransfer method. Furthermore, the power receiving unit 291 may receivepower according to at least one wireless power transfer method, and inthis case, the power receiving unit 291 may include constituent elementsrequired for each method.

First, the power receiving unit 291 may include a coil for receiving awireless power signal transferred in the form of a magnetic field orelectromagnetic field having a vibration characteristic.

For instance, as a constituent element according to the inductivecoupling method, the power receiving unit 291 may include a secondarycoil to which a current is induced by a changing magnetic field. Inexemplary embodiments, the power receiving unit 291, as a constituentelement according to the resonance coupling method, may include a coiland a resonant circuit in which resonance phenomenon is generated by amagnetic field having a specific resonant frequency.

In another exemplary embodiments, when the power receiving unit 291receives power according to at least one wireless power transfer method,the power receiving unit 291 may be implemented to receive power byusing a coil, or implemented to receive power by using a coil formeddifferently according to each power transfer method.

Among the constituent elements included in the power receiving unit 291,those for the inductive coupling method will be described later withreference to FIG. 4, and those for the resonance coupling method withreference to FIG. 7.

On the other hand, the power receiving unit 291 may further include arectifier and a regulator to convert the wireless power signal into adirect current. Furthermore, the power receiving unit 291 may furtherinclude a circuit for protecting an overvoltage or overcurrent frombeing generated by the received power signal.

The power reception control unit 292 may control each constituentelement included in the power supply unit 290.

Specifically, the power reception control unit 292 may transfer a powercontrol message to the wireless power transmitter 100. The power controlmessage may instruct the wireless power transmitter 100 to initiate orterminate a transfer of the wireless power signal. Furthermore, thepower control message may instruct the wireless power transmitter 100 tocontrol a characteristic of the wireless power signal.

In exemplary embodiments, the power reception control unit 292 maytransmit the power control message through at least one of the wirelesspower signal and user data.

In order to transmit the foregoing power control message, the wirelesspower receiver 200 may further include a modulation/demodulation unit293 electrically connected to the power receiving unit 291. Themodulation/demodulation unit 293, similarly to the case of the wirelesspower transmitter 100, may be used to transmit the power control messagethrough the wireless power signal. The power communicationsmodulation/demodulation unit 293 may be used as a means for controllinga current and/or voltage flowing through the power conversion unit 111of the wireless power transmitter 100. Hereinafter, a method forallowing the power communications modulation/demodulation unit 113 or293 at the side of the wireless power transmitter 100 and at the side ofthe wireless power receiver 200, respectively, to be used to transmitand receive a power control message through a wireless power signal willbe described.

A wireless power signal formed by the power conversion unit 111 isreceived by the power receiving unit 291. At this time, the powerreception control unit 292 controls the power communicationsmodulation/demodulation unit 293 at the side of the wireless powerreceiver 200 to modulate the wireless power signal. For instance, thepower reception control unit 292 may perform a modulation process suchthat a power amount received from the wireless power signal is varied bychanging a reactance of the power communications modulation/demodulationunit 293 connected to the power receiving unit 291. The change of apower amount received from the wireless power signal results in thechange of a current and/or voltage of the power conversion unit 111 forforming the wireless power signal. At this time, themodulation/demodulation unit 113 at the side of the wireless powertransmitter 100 may detect a change of the current and/or voltage toperform a demodulation process.

In other words, the power reception control unit 292 may generate apacket including a power control message intended to be transferred tothe wireless power transmitter 100 and modulate the wireless powersignal to allow the packet to be included therein, and the powertransmission control unit 112 may decode the packet based on a result ofperforming the demodulation process of the power communicationsmodulation/demodulation unit 113 to acquire the power control messageincluded in the packet.

In addition, the power reception control unit 292 may transmit a powercontrol message to the wireless power transmitter 100 by transmittinguser data including the power control message by a communication means(not shown) included in the wireless power receiver 200.

[For Supporting in-Band Two-Way Communication]

Under a wireless power transfer environment allowing for bi-directionalcommunications according to the exemplary embodiments disclosed herein,the power reception control unit 292 may receive data to the wirelesspower transmitter 100. The data transmitted by the wireless powertransmitter 100 may be transmitted to request the wireless powerreceiver 200 to send the power control message.

In addition, the power supply unit 290 may further include a charger 298and a battery 299.

The wireless power receiver 200 receiving power for operation from thepower supply unit 290 may be operated by power transferred from thewireless power transmitter 100, or operated by charging the battery 299using the transferred power and then receiving the charged power. Atthis time, the power reception control unit 292 may control the charger298 to perform charging using the transferred power.

Hereinafter, description will be given of a wireless power transmitterand a wireless power receiver applicable to the exemplary embodimentsdisclosed herein. First, a method of allowing the wireless powertransmitter to transfer power to the electronic device according to theinductive coupling method will be described with reference to FIGS. 3through 5.

Inductive Coupling Method

FIG. 3 is a view illustrating a concept in which power is transferredfrom a wireless power transmitter to an electronic device in a wirelessmanner according to an inductive coupling method.

When the power of the wireless power transmitter 100 is transferred inan inductive coupling method, if the strength of a current flowingthrough a primary coil within the power transmission unit 110 ischanged, then a magnetic field passing through the primary coil will bechanged by the current. The changed magnetic field generates an inducedelectromotive force at a secondary coil in the wireless power receiver200.

According to the foregoing method, the power conversion unit 111 of thewireless power transmitter 100 may include a transmitting (Tx) coil 1111a being operated as a primary coil in magnetic induction. Furthermore,the power receiving unit 291 of the wireless power receiver 200 mayinclude a receiving (Rx) coil 2911 a being operated as a secondary coilin magnetic induction.

First, the wireless power transmitter 100 and wireless power receiver200 are disposed in such a manner that the transmitting coil 1111 a atthe side of the wireless power transmitter 100 and the receiving coil atthe side of the wireless power receiver 200 are located adjacent to eachother. Then, if the power transmission control unit 112 controls acurrent of the transmitting coil (Tx coil) 1111 a to be changed, thenthe power receiving unit 291 controls power to be supplied to thewireless power receiver 200 using an electromotive force induced to thereceiving coil (Rx coil) 2911 a.

The efficiency of wireless power transfer by the inductive couplingmethod may be little affected by a frequency characteristic, butaffected by an alignment and distance between the wireless powertransmitter 100 and the wireless power receiver 200 including each coil.

On the other hand, in order to perform wireless power transfer in theinductive coupling method, the wireless power transmitter 100 may beconfigured to include an interface surface (not shown) in the form of aflat surface. One or more electronic devices may be placed at an upperportion of the interface surface, and the transmitting coil 1111 a maybe mounted at a lower portion of the interface surface. In this case, avertical spacing is formed in a small-scale between the transmittingcoil 1111 a mounted at a lower portion of the interface surface and thereceiving coil 2911 a of the wireless power receiver 200 placed at anupper portion of the interface surface, and thus a distance between thecoils becomes sufficiently small to efficiently implement contactlesspower transfer by the inductive coupling method.

Furthermore, an alignment indicator (not shown) indicating a locationwhere the wireless power receiver 200 is to be placed at an upperportion of the interface surface. The alignment indicator indicates alocation of the wireless power receiver 200 where an alignment betweenthe transmitting coil 1111 a mounted at a lower portion of the interfacesurface and the receiving coil 2911 a can be suitably implemented. Thealignment indicator may alternatively be simple marks, or may be formedin the form of a protrusion structure for guiding the location of thewireless power receiver 200. Otherwise, the alignment indicator may beformed in the form of a magnetic body such as a magnet mounted at alower portion of the interface surface, thereby guiding the coils to besuitably arranged by mutual magnetism to a magnetic body having anopposite polarity mounted within the wireless power receiver 200.

On the other hand, the wireless power transmitter 100 may be formed toinclude one or more transmitting coils. The wireless power transmitter100 may selectively use some of coils suitably arranged with thereceiving coil 2911 a of the wireless power receiver 200 among the oneor more transmitting coils to enhance the power transmission efficiency.The wireless power transmitter 100 including the one or moretransmitting coils will be described later with reference to FIG. 5.

Hereinafter, configurations of the wireless power transmitter andelectronic device using an inductive coupling method applicable to theembodiments disclosed herein will be described in detail.

Wireless Power Transmitter and Electronic Device in Inductive CouplingMethod

FIG. 4 is a block diagram illustrating part of the wireless powertransmitter 100 and wireless power receiver 200 in a magnetic inductionmethod that can be employed in the embodiments disclosed herein. Aconfiguration of the power transmission unit 110 included in thewireless power transmitter 100 will be described with reference to FIG.4A, and a configuration of the power supply unit 290 included in thewireless power receiver 200 will be described with reference to FIG. 4B.

Referring to FIG. 4A, the power conversion unit 111 of the wirelesspower transmitter 100 may include a transmitting (Tx) coil 1111 a and aninverter 1112.

The transmitting coil 1111 a may form a magnetic field corresponding tothe wireless power signal according to a change of current as describedabove. The transmitting coil 1111 a may alternatively be implementedwith a planar spiral type or cylindrical solenoid type.

The inverter 1112 transforms a DC input obtained from the power supplyunit 190 into an AC waveform. The AC current transformed by the inverter1112 drives a resonant circuit including the transmitting coil 1111 aand a capacitor (not shown) to form a magnetic field in the transmittingcoil 1111 a.

In addition, the power conversion unit 111 may further include apositioning unit 1114.

The positioning unit 1114 may move or rotate the transmitting coil 1111a to enhance the effectiveness of contactless power transfer using theinductive coupling method. As described above, it is because analignment and distance between the wireless power transmitter 100 andthe wireless power receiver 200 including a primary coil and a secondarycoil may affect power transfer using the inductive coupling method. Inparticular, the positioning unit 1114 may be used when the wirelesspower receiver 200 does not exist within an active area of the wirelesspower transmitter 100.

Accordingly, the positioning unit 1114 may include a drive unit (notshown) for moving the transmitting coil 1111 a such that acenter-to-center distance of the transmitting coil 1111 a of thewireless power transmitter 100 and the receiving coil 2911 a of thewireless power receiver 200 is within a predetermined range, or rotatingthe transmitting coil 1111 a such that the centers of the transmittingcoil 1111 a and the receiving coil 2911 a are overlapped with eachother.

For this purpose, the wireless power transmitter 100 may further includea detection unit (not shown) made of a sensor for detecting the locationof the wireless power receiver 200, and the power transmission controlunit 112 may control the positioning unit 1114 based on the locationinformation of the wireless power receiver 200 received from thelocation detection sensor.

Furthermore, to this end, the power transmission control unit 112 mayreceive control information on an alignment or distance to the wirelesspower receiver 200 through the power communicationsmodulation/demodulation unit 113, and control the positioning unit 1114based on the received control information on the alignment or distance.

If the power conversion unit 111 is configured to include a plurality oftransmitting coils, then the positioning unit 1114 may determine whichone of the plurality of transmitting coils is to be used for powertransmission. The configuration of the wireless power transmitter 100including the plurality of transmitting coils will be described laterwith reference to FIG. 5.

On the other hand, the power conversion unit 111 may further include apower sensing unit 1115. The power sensing unit 1115 at the side of thewireless power transmitter 100 monitors a current or voltage flowinginto the transmitting coil 1111 a. The power sensing unit 1115 isprovided to check whether or not the wireless power transmitter 100 isnormally operated, and thus the power sensing unit 1115 may detect avoltage or current of the power supplied from the outside, and checkwhether the detected voltage or current exceeds a threshold value. Thepower sensing unit 1115, although not shown, may include a resistor fordetecting a voltage or current of the power supplied from the outsideand a comparator for comparing a voltage value or current value of thedetected power with a threshold value to output the comparison result.Based on the check result of the power sensing unit 1115, the powertransmission control unit 112 may control a switching unit (not shown)to cut off power applied to the transmitting coil 1111 a.

Referring to FIG. 4B, the power supply unit 290 of the wireless powerreceiver 200 may include a receiving (Rx) coil 2911 a and a rectifier2913.

A current is induced into the receiving coil 2911 a by a change of themagnetic field formed in the transmitting coil 1111 a. Theimplementation type of the receiving coil 2911 a may be a planar spiraltype or cylindrical solenoid type similarly to the transmitting coil1111 a.

Furthermore, series and parallel capacitors may be configured to beconnected to the receiving coil 2911 a to enhance the effectiveness ofwireless power reception or perform resonant detection.

The receiving coil 2911 a may be in the form of a single coil or aplurality of coils.

The rectifier 2913 performs a full-wave rectification to a current toconvert alternating current into direct current. The rectifier 2913, forinstance, may be implemented with a full-bridge rectifier made of fourdiodes or a circuit using active components.

In addition, the rectifier 2913 may further include a regulator forconverting a rectified current into a more flat and stable directcurrent. Furthermore, the output power of the rectifier 2913 is suppliedto each constituent element of the power supply unit 290. Furthermore,the rectifier 2913 may further include a DC-DC converter for convertingoutput DC power into a suitable voltage to adjust it to the powerrequired for each constituent element (for instance, a circuit such as acharger 298).

The power communications modulation/demodulation unit 293 may beconnected to the power receiving unit 291, and may be configured with aresistive element in which resistance varies with respect to directcurrent, and may be configured with a capacitive element in whichreactance varies with respect to alternating current. The powerreception control unit 292 may change the resistance or reactance of thepower communications modulation/demodulation unit 293 to modulate awireless power signal received to the power receiving unit 291.

On the other hand, the power supply unit 290 may further include a powersensing unit 2914. The power sensing unit 2914 at the side of thewireless power receiver 200 monitors a voltage and/or current of thepower rectified by the rectifier 2913, and if the voltage and/or currentof the rectified power exceeds a threshold value as a result ofmonitoring, then the power reception control unit 292 transmits a powercontrol message to the wireless power transmitter 100 to transfersuitable power.

Wireless Power Transmitter Configured to Include One or MoreTransmitting Coils

FIG. 5 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to an inductive coupling method that can be employed in theembodiments disclosed herein.

Referring to FIG. 5, the power conversion unit 111 of the wireless powertransmitter 100 according to the embodiments disclosed herein mayinclude one or more transmitting coils 1111 a-1 to 1111 a-n. The one ormore transmitting coils 1111 a-1 to 1111 a-n may be an array of partlyoverlapping primary coils. An active area may be determined by some ofthe one or more transmitting coils.

The one or more transmitting coils 1111 a-1 to 1111 a-n may be mountedat a lower portion of the interface surface. Furthermore, the powerconversion unit 111 may further include a multiplexer 1113 forestablishing and releasing the connection of some of the one or moretransmitting coils 1111 a-1 to 1111 a-n.

Upon detecting the location of the wireless power receiver 200 placed atan upper portion of the interface surface, the power transmissioncontrol unit 112 may take the detected location of the wireless powerreceiver 200 into consideration to control the multiplexer 1113, therebyallowing coils that can be placed in an inductive coupling relation tothe receiving coil 2911 a of the wireless power receiver 200 among theone or more transmitting coils 1111 a-1 to 1111 a-n to be connected toone another.

For this purpose, the power transmission control unit 112 may acquirethe location information of the wireless power receiver 200. Forexample, the power transmission control unit 112 may acquire thelocation of the wireless power receiver 200 on the interface surface bythe location detection unit (not shown) provided in the wireless powertransmitter 100. For another example, the power transmission controlunit 112 may alternatively receive a power control message indicating astrength of the wireless power signal from an object on the interfacesurface or a power control message indicating the identificationinformation of the object using the one or more transmitting coils 1111a-1 to 1111 a-n, respectively, and determines whether it is locatedadjacent to which one of the one or more transmitting coils based on thereceived result, thereby acquiring the location information of thewireless power receiver 200.

On the other hand, the active area as part of the interface surface maydenote a portion through which a magnetic field with a high efficiencycan pass when the wireless power transmitter 100 transfers power to thewireless power receiver 200 in a wireless manner. At this time, a singletransmitting coil or one or a combination of more transmitting coilsforming a magnetic field passing through the active area may bedesignated as a primary cell. Accordingly, the power transmissioncontrol unit 112 may determine an active area based on the detectedlocation of the wireless power receiver 200, and establish theconnection of a primary cell corresponding to the active area to controlthe multiplexer 1113, thereby allowing the receiving coil 2911 a of thewireless power receiver 200 and the coils belonging to the primary cellto be placed in an inductive coupling relation.

Furthermore, the power conversion unit 111 may further include animpedance matching unit (not shown) for controlling an impedance to forma resonant circuit with the coils connected thereto.

Hereinafter, a method for allowing a wireless power transmitter totransfer power according to a resonance coupling method will bedisclosed with reference to FIGS. 6 through 8.

Resonance Coupling Method

FIG. 6 is a view illustrating a concept in which power is transferred toan electronic device from a wireless power transmitter in a wirelessmanner according to a resonance coupling method.

First, resonance will be described in brief as follows. Resonance refersto a phenomenon in which amplitude of vibration is remarkably increasedwhen periodically receiving an external force having the same frequencyas the natural frequency of a vibration system. Resonance is aphenomenon occurring at all kinds of vibrations such as mechanicalvibration, electric vibration, and the like. Generally, when exerting avibratory force to a vibration system from the outside, if the naturalfrequency thereof is the same as a frequency of the externally appliedforce, then the vibration becomes strong, thus increasing the width.

With the same principle, when a plurality of vibrating bodies separatedfrom one another within a predetermined distance vibrate at the samefrequency, the plurality of vibrating bodies resonate with one another,and in this case, resulting in a reduced resistance between theplurality of vibrating bodies. In an electrical circuit, a resonantcircuit can be made by using an inductor and a capacitor.

When the wireless power transmitter 100 transfers power according to theinductive coupling method, a magnetic field having a specific vibrationfrequency is formed by alternating current power in the powertransmission unit 110. If a resonance phenomenon occurs in the wirelesspower receiver 200 by the formed magnetic field, then power is generatedby the resonance phenomenon in the wireless power receiver 200.

The resonant frequency may be determined by the following formula inEquation 1.

$\begin{matrix}{f = \frac{1}{2\; \pi \sqrt{LC}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Here, the resonant frequency (f) is determined by an inductance (L) anda capacitance (C) in a circuit. In a circuit forming a magnetic fieldusing a coil, the inductance can be determined by a number of turns ofthe coil, and the like, and the capacitance can be determined by a gapbetween the coils, an area, and the like. In addition to the coil, acapacitive resonant circuit may be configured to be connected thereto todetermine the resonant frequency.

Referring to FIG. 6, when power is transmitted in a wireless manneraccording to the resonance coupling method, the power conversion unit111 of the wireless power transmitter 100 may include a transmitting(Tx) coil 1111 b in which a magnetic field is formed and a resonantcircuit 1116 connected to the transmitting coil 1111 b to determine aspecific vibration frequency. The resonant circuit 1116 may beimplemented by using a capacitive circuit (capacitors), and the specificvibration frequency may be determined based on an inductance of thetransmitting coil 1111 b and a capacitance of the resonant circuit 1116.

The configuration of a circuit element of the resonant circuit 1116 maybe implemented in various forms such that the power conversion unit 111forms a magnetic field, and is not limited to a form of being connectedin parallel to the transmitting coil 1111 b as illustrated in FIG. 6.

Furthermore, the power receiving unit 291 of the wireless power receiver200 may include a resonant circuit 2912 and a receiving (Rx) coil 2911 bto generate a resonance phenomenon by a magnetic field formed in thewireless power transmitter 100. In other words, the resonant circuit2912 may be also implemented by using a capacitive circuit, and theresonant circuit 2912 is configured such that a resonant frequencydetermined based on an inductance of the receiving coil 2911 b and acapacitance of the resonant circuit 2912 has the same frequency as aresonant frequency of the formed magnetic field.

The configuration of a circuit element of the resonant circuit 2912 maybe implemented in various forms such that the power receiving unit 291generates resonance by a magnetic field, and is not limited to a form ofbeing connected in series to the receiving coil 2911 b as illustrated inFIG. 6.

The specific vibration frequency in the wireless power transmitter 100may have L_(TX), C_(TX), and may be acquired by using the Equation 1.Here, the wireless power receiver 200 generates resonance when a resultof substituting the L_(RX) and C_(RX) of the wireless power receiver 200to the Equation 1 is same as the specific vibration frequency.

According to a contactless power transfer method by resonance coupling,when the wireless power transmitter 100 and wireless power receiver 200resonate at the same frequency, respectively, an electromagnetic wave ispropagated through a short-range magnetic field, and thus there existsno energy transfer between the devices if they have differentfrequencies.

As a result, an efficiency of contactless power transfer by theresonance coupling method is greatly affected by a frequencycharacteristic, whereas the effect of an alignment and distance betweenthe wireless power transmitter 100 and the wireless power receiver 200including each coil is relatively smaller than the inductive couplingmethod.

Hereinafter, the configuration of a wireless power transmitter and anelectronic device in the resonance coupling method applicable to theembodiments disclosed herein will be described in detail.

Wireless Power Transmitter in Resonance Coupling Method

FIG. 7 is a block diagram Illustrating part of the wireless powertransmitter 100 and wireless power receiver 200 in a resonance methodthat can be employed in the embodiments disclosed herein.

A configuration of the power transmission unit 110 included in thewireless power transmitter 100 will be described with reference to FIG.7A.

The power conversion unit 111 of the wireless power transmitter 100 mayinclude a transmitting (Tx) coil 1111 b, an inverter 1112, and aresonant circuit 1116. The inverter 1112 may be configured to beconnected to the transmitting coil 1111 b and the resonant circuit 1116.

The transmitting coil 1111 b may be mounted separately from thetransmitting coil 1111 a for transferring power according to theinductive coupling method, but may transfer power in the inductivecoupling method and resonance coupling method using one single coil.

The transmitting coil 1111 b, as described above, forms a magnetic fieldfor transferring power. The transmitting coil 1111 b and the resonantcircuit 1116 generate resonance when alternating current power isapplied thereto, and at this time, a vibration frequency may bedetermined based on an inductance of the transmitting coil 1111 b and acapacitance of the resonant circuit 1116.

For this purpose, the inverter 1112 transforms a DC input obtained fromthe power supply unit 190 into an AC waveform, and the transformed ACcurrent is applied to the transmitting coil 1111 b and the resonantcircuit 1116.

In addition, the power conversion unit 111 may further include afrequency adjustment unit 1117 for changing a resonant frequency of thepower conversion unit 111. The resonant frequency of the powerconversion unit 111 is determined based on an inductance and/orcapacitance within a circuit constituting the power conversion unit 111by Equation 1, and thus the power transmission control unit 112 maydetermine the resonant frequency of the power conversion unit 111 bycontrolling the frequency adjustment unit 1117 to change the inductanceand/or capacitance.

The frequency adjustment unit 1117, for example, may be configured toinclude a motor for adjusting a distance between capacitors included inthe resonant circuit 1116 to change a capacitance, or include a motorfor adjusting a number of turns or diameter of the transmitting coil1111 b to change an inductance, or include active elements fordetermining the capacitance and/or inductance

On the other hand, the power conversion unit 111 may further include apower sensing unit 1115. The operation of the power sensing unit 1115 isthe same as the foregoing description.

Referring to FIG. 78, a configuration of the power supply unit 290included in the wireless power receiver 200 will be described. The powersupply unit 290, as described above, may include the receiving (Rx) coil2911 b and resonant circuit 2912.

In addition, the power receiving unit 291 of the power supply unit 290may further include a rectifier 2913 for converting an AC currentgenerated by resonance phenomenon into DC. The rectifier 2913 may beconfigured similarly to the foregoing description.

Furthermore, the power receiving unit 291 may further include a powersensing unit 2914 for monitoring a voltage and/or current of therectified power. The power sensing unit 2914 may be configured similarlyto the foregoing description.

Wireless Power Transmitter Configured to Include One or MoreTransmitting Coils

FIG. 8 is a block diagram illustrating a wireless power transmitterconfigured to have one or more transmission coils receiving poweraccording to a resonance coupling method that can be employed in theembodiments disclosed herein.

Referring to FIG. 8, the power conversion unit 111 of the wireless powertransmitter 100 according to the embodiments disclosed herein mayinclude one or more transmitting coils 1111 b-1 to 1111 b-n and resonantcircuits (1116-1 to 1116-n) connected to each transmitting coils.Furthermore, the power conversion unit 111 may further include amultiplexer 1113 for establishing and releasing the connection of someof the one or more transmitting coils 1111 b-1 to 1111 b-n.

The one or more transmitting coils 1111 b-1 to 1111 b-n may beconfigured to have the same vibration frequency, or some of them may beconfigured to have different vibration frequencies. It is determined byan inductance and/or capacitance of the resonant circuits (1116-1 to1116-n) connected to the one or more transmitting coils 1111 b-1 to 1111b-n, respectively.

For this purpose, the frequency adjustment unit 1117 may be configuredto change an inductance and/or capacitance of the resonant circuits(1116-1 to 1116-n) connected to the one or more transmitting coils 1111b-1 to 1111 b-n, respectively.

In-Band Communication

FIG. 9 a view illustrating the concept of transmitting and receiving apacket between a wireless power transmitter and a wireless powerreceiver through the modulation and demodulation of a wireless powersignal in transferring power in a wireless manner disclosed herein.

As illustrated in FIG. 9, the power conversion unit 111 included in thewireless power transmitter 100 may generate a wireless power signal. Thewireless power signal may be generated through the transmitting coil1111 included in the power conversion unit 111.

The wireless power signal 10 a generated by the power conversion unit111 may arrive at the wireless power receiver 200 so as to be receivedthrough the power receiving unit 291 of the wireless power receiver 200.The generated wireless power signal may be received through thereceiving coil 2911 Included in the power receiving unit 291.

The power reception control unit 292 may control themodulation/demodulation unit 293 connected to the power receiving unit291 to modulate the wireless power signal while the wireless powerreceiver 200 receives the wireless power signal. When the receivedwireless power signal is modulated, the wireless power signal may form aclosed-loop within a magnetic field or an electro-magnetic field. Thismay allow the wireless power transmitter 100 to sense a modulatedwireless power signal 10 b. The modulation/demodulation unit 113 maydemodulate the sensed wireless power signal and decode the packet fromthe demodulated wireless power signal.

The modulation method employed for the communication between thewireless power transmitter 100 and the wireless power receiver 200 maybe an amplitude modulation. As aforementioned, the amplitude modulationis a backscatter modulation may be a backscatter modulation method inwhich the power communications modulation/demodulation unit 293 at theside of the wireless power receiver 200 changes an amplitude of thewireless power signal 10 a formed by the power conversion unit 111 andthe power reception control unit 292 at the side of the wireless powertransmitter 100 detects an amplitude of the modulated wireless powersignal 10 b.

Modulation and Demodulation of Wireless Power Signal

Hereinafter, description will be given of modulation and demodulation ofa packet, which is transmitted or received between the wireless powertransmitter 100 and the wireless power receiver 200 with reference toFIGS. 10 and 11.

FIG. 10 is a view Illustrating a configuration of transmitting orreceiving a power control message in transferring power in a wirelessmanner disclosed herein, and FIG. 11 is a view illustrating forms ofsignals upon modulation and demodulation executed in the wireless powertransfer disclosed herein.

Referring to FIG. 10, the wireless power signal received through thepower receiving unit 291 of the wireless power receiver 200, asillustrated in FIG. 11A, may be a non-modulated wireless power signal51. The wireless power receiver 200 and the wireless power transmitter100 may establish a resonance coupling according to a resonantfrequency, which is set by the resonant circuit 2912 within the powerreceiving unit 291, and the wireless power signal 51 may be receivedthrough the receiving coil 2911 b.

The power reception control unit 292 may modulate the wireless powersignal 51 received through the power receiving unit 291 by changing aload impedance within the modulation/demodulation unit 293. Themodulation/demodulation unit 293 may include a passive element 2931 andan active element 2932 for modulating the wireless power signal 51. Themodulation/demodulation unit 293 may modulate the wireless power signal51 to include a packet, which is desired to be transmitted to thewireless power transmitter 100. Here, the packet may be input into theactive element 2932 within the modulation/demodulation unit 293.

Afterwards, the power transmission control unit 112 of the wirelesspower transmitter 100 may demodulate a modulated wireless power signal52 through an envelop detection, and decode the detected signal 53 intodigital data 54. The demodulation may detect a current or voltageflowing into the power conversion unit 111 to be classified into twostates, a HI phase and a LO phase, and acquire a packet to betransmitted by the wireless power receiver 200 based on digital dataclassified according to the states.

Hereinafter, a process of allowing the wireless power transmitter 100 toacquire a power control message to be transmitted by the wireless powerreceiver 200 from the demodulated digital data will be described.

Referring to FIG. 11B, the power transmission control unit 112 detectsan encoded bit using a clock signal (CLK) from an envelope detectedsignal. The detected encoded bit is encoded according to a bit encodingmethod used in the modulation process at the side of the wireless powerreceiver 200. The bit encoding method may correspond to any one ofnon-return to zero (NRZ) and bi-phase encoding.

For instance, the detected bit may be a differential bi-phase (DBP)encoded bit. According to the DBP encoding, the power reception controlunit 292 at the side of the wireless power receiver 200 is allowed tohave two state transitions to encode data bit 1, and to have one statetransition to encode data bit 0. In other words, data bit 1 may beencoded in such a manner that a transition between the HI state and LOstate is generated at a rising edge and falling edge of the clocksignal, and data bit 0 may be encoded in such a manner that a transitionbetween the HI state and LO state is generated at a rising edge of theclock signal.

On the other hand, the power transmission control unit 112 may acquiredata in a byte unit using a byte format constituting a packet from a bitstring detected according to the bit encoding method. For instance, thedetected bit string may be transferred by using an 11-bit asynchronousserial format as illustrated in FIG. 12C. In other words, the detectedbit may include a start bit indicating the beginning of a byte and astop bit indicating the end of a byte, and also include data bits (b0 tob7) between the start bit and the stop bit. Furthermore, it may furtherinclude a parity bit for checking an error of data. The data in a byteunit constitutes a packet including a power control message.

[for Supporting in-Band Two-Way Communication]

As aforementioned, FIG. 9 has illustrated that the wireless powerreceiver 200 transmits a packet using a carrier signal 10 a formed bythe wireless power transmitter 100. However, the wireless powertransmitter 100 may also transmit data to the wireless power receiver200 by a similar method.

That is, the power transmission control unit 112 may control themodulation/demodulation unit 113 to modulate data, which is to betransmitted to the wireless power receiver 200, such that the data canbe included in the carrier signal 10 a. Here, the power receptioncontrol unit 292 of the wireless power receiver 200 may control themodulation/demodulation unit 293 to execute demodulation so as toacquire data from the modulated carrier signal 10 a.

Packet Format

Hereinafter, description will be given of a structure of a packet usedin communication using a wireless power signal according to theexemplary embodiments disclosed herein.

FIG. 12 is a view illustrating a packet including a power controlmessage used in a contactless (wireless) power transfer method accordingto the embodiments disclosed herein.

As illustrated in FIG. 12A, the wireless power transmitter 100 and thewireless power receiver 200 may transmit and receive data desired totransmit in a form of a command packet (command_packet) 510. The commandpacket 510 may include a header 511 and a message 512.

The header 511 may include a field indicating a type of data included inthe message 512. Size and type of the message may be decided based on avalue of the field which indicates the type of data.

The header 511 may include an address field for identifying atransmitter (originator) of the packet. For example, the address fieldmay indicate an identifier of the wireless power receiver 200 or anidentifier of a group to which the wireless power receiver 200 belongs.When the wireless power receiver 200 transmits the packet 510, thewireless power receiver 200 may generate the packet 510 such that theaddress field can indicate identification Information related to thereceiver 200 itself.

The message 512 may include data that the originator of the packet 510desires to transmit. The data included in the message 512 may be areport, a request or a response for the other party.

According to one exemplary embodiment, the command packet 510 may beconfigured as illustrated in FIG. 12B. The header 511 included in thecommand packet 510 may be represented with a predetermined size. Forexample, the header 511 may have a 2-byte size.

The header 511 may include a reception address field. For example, thereception address field may have a 6-bit size.

The header 511 may include an operation command field (OCF) or anoperation group field (OGF). The OGF is a value given for each group ofcommands for the wireless power receiver 200, and the OCF is a valuegiven for each command existing in each group in which the wirelesspower receiver 200 is included.

The message 512 may be divided into a length field 5121 of a parameterand a value field 5122 of the parameter. That is, the originator of thepacket 510 may generate the message by a length-value pair (5121 a-5122a, etc.) of at least one parameter, which is required to represent datadesired to transmit.

Referring to FIG. 12C, the wireless power transmitter 100 and thewireless power receiver 200 may transmit and receive the data in a formof a packet which further has a preamble 520 and a checksum 530 added tothe command packet 510.

The preamble 520 may be used to perform synchronization with datareceived by the wireless power transmitter 100 and detect the start bitof the header 520. The preamble 520 may be configured to repeat the samebit. For instance, the preamble 520 may be configured such that data bit1 according to the DBP encoding is repeated eleven to twenty five times.

The checksum 530 may be used to detect an error that can be occurred inthe command packet 510 while transmitting a power control message.

Operation Phases

Hereinafter, description will be given of operation phases of thewireless power transmitter 100 and the wireless power receiver 200.

FIG. 13 illustrates the operation phases of the wireless powertransmitter 100 and the wireless power receiver 200 according to theembodiments disclosed herein. Furthermore, FIGS. 14 to 18 illustrate thestructures of packets including a power control message between thewireless power transmitter 100 and the wireless power receiver 200.

Referring to FIG. 13, the operation phases of the wireless powertransmitter 100 and the wireless power receiver 200 for wireless powertransfer may be divided into a selection phase (state) 610, a ping phase620, an identification and configuration phase 630, and a power transferphase 640.

The wireless power transmitter 100 detects whether or not objects existwithin a range that the wireless power transmitter 100 can transmitpower in a wireless manner in the selection state 610, and the wirelesspower transmitter 100 sends a detection signal to the detected objectand the wireless power receiver 200 sends a response to the detectionsignal in the ping state 620.

Furthermore, the wireless power transmitter 100 identifies the wirelesspower receiver 200 selected through the previous states and acquiresconfiguration information for power transmission in the identificationand configuration state 630. The wireless power transmitter 100transmits power to the wireless power receiver 200 while controllingpower transmitted in response to a control message received from thewireless power receiver 200 in the power transfer state 640.

Hereinafter, each of the operation phases will be described in detail.

1) Selection State

The wireless power transmitter 100 in the selection state 610 performs adetection process to select the wireless power receiver 200 existingwithin a detection area. The detection area, as described above, refersto a region in which an object within the relevant area can affect onthe characteristic of the power of the power conversion unit 111.Compared to the ping state 620, the detection process for selecting thewireless power receiver 200 in the selection state 610 is a process ofdetecting a change of the power amount for forming a wireless powersignal in the power conversion unit at the side of the wireless powertransmitter 100 to check whether any object exists within apredetermined range, instead of the scheme of receiving a response fromthe wireless power receiver 200 using a power control message. Thedetection process in the selection state 610 may be referred to as ananalog ping process in the aspect of detecting an object using awireless power signal without using a packet in a digital format in theping state 620 which will be described later.

The wireless power transmitter 100 in the selection state 610 can detectthat an object comes in or out within the detection area. Furthermore,the wireless power transmitter 100 can distinguish the wireless powerreceiver 200 capable of transferring power in a wireless manner fromother objects (for example, a key, a coin, etc.) among objects locatedwithin the detection area.

As described above, a distance that can transmit power in a wirelessmanner may be different according to the inductive coupling method andresonance coupling method, and thus the detection area for detecting anobject in the selection state 610 may be different from one another.

First, in case where power is transmitted according to the inductivecoupling method, the wireless power transmitter 100 in the selectionstate 610 can monitor an interface surface (not shown) to detect thealignment and removal of objects.

Furthermore, the wireless power transmitter 100 may detect the locationof the wireless power receiver 200 placed on an upper portion of theinterface surface. As described above, the wireless power transmitter100 formed to include one or more transmitting coils may perform theprocess of entering the ping state 620 in the selection state 610, andchecking whether or not a response to the detection signal istransmitted from the object using each coil in the ping state 620 orsubsequently entering the identification state 630 to check whetheridentification information is transmitted from the object. The wirelesspower transmitter 100 may determine a coil to be used for contactlesspower transfer based on the detected location of the wireless powerreceiver 200 acquired through the foregoing process.

Furthermore, when power is transmitted according to the resonancecoupling method, the wireless power transmitter 100 in the selectionstate 610 can detect an object by detecting that any one of a frequency,a current and a voltage of the power conversion unit is changed due toan object located within the detection area.

On the other hand, the wireless power transmitter 100 in the selectionstate 610 may detect an object by at least any one of the detectionmethods using the inductive coupling method and resonance couplingmethod. The wireless power transmitter 100 may perform an objectdetection process according to each power transmission method, andsubsequently select a method of detecting the object from the couplingmethods for contactless power transfer to advance to other states 620,630, 640.

On the other hand, for the wireless power transmitter 100, a wirelesspower signal formed to detect an object in the selection state 610 and awireless power signal formed to perform digital detection,identification, configuration and power transmission in the subsequentstates 620, 630, 640 may have a different characteristic in thefrequency, strength, and the like. It is because the selection state 610of the wireless power transmitter 100 corresponds to an idle state fordetecting an object, thereby allowing the wireless power transmitter 100to reduce consumption power in the idle state or generate a specializedsignal for effectively detecting an object.

2) Ping State

The wireless power transmitter 100 in the ping state 620 performs aprocess of detecting the wireless power receiver 200 existing within thedetection area through a power control message. Compared to thedetection process of the wireless power receiver 200 using acharacteristic of the wireless power signal and the like in theselection state 610, the detection process in the ping state 620 may bereferred to as a digital ping process.

The wireless power transmitter 100 in the ping state 620 forms awireless power signal to detect the wireless power receiver 200,modulates the wireless power signal modulated by the wireless powerreceiver 200, and acquires a power control message in a digital dataformat corresponding to a response to the detection signal from themodulated wireless power signal. The wireless power transmitter 100 mayreceive a power control message corresponding to the response to thedetection signal to recognize the wireless power receiver 200 which is asubject of power transmission.

The detection signal formed to allowing the wireless power transmitter100 in the ping state 620 to perform a digital detection process may bea wireless power signal formed by applying a power signal at a specificoperating point for a predetermined period of time. The operating pointmay denote a frequency, duty cycle, and amplitude of the voltage appliedto the transmitting (Tx) coil. The wireless power transmitter 100 maygenerate the detection signal generated by applying the power signal ata specific operating point for a predetermined period of time, andattempt to receive a power control message from the wireless powerreceiver 200.

On the other hand, the power control message corresponding to a responseto the detection signal may be a message indicating strength of thewireless power signal received by the wireless power receiver 200. Forexample, the wireless power receiver 200 may transmit a signal strengthpacket 5100 including a message indicating the received strength of thewireless power signal as a response to the detection signal asillustrated in FIG. 15. The packet 5100 may include a header 5120 fornotifying a packet indicating the signal strength and a message 5130indicating strength of the power signal received by the wireless powerreceiver 200. The strength of the power signal within the message 5130may be a value indicating a degree of inductive coupling or resonancecoupling for power transmission between the wireless power transmitter100 and the wireless power receiver 200.

The wireless power transmitter 100 may receive a response message to thedetection signal to find the wireless power receiver 200, and thenextend the digital detection process to enter the identification andconfiguration state 630. In other words, the wireless power transmitter100 maintains the power signal at a specific operating point subsequentto finding the wireless power receiver 200 to receive a power controlmessage required in the identification and configuration state 630.

However, if the wireless power transmitter 100 is not able to find thewireless power receiver 200 to which power can be transferred, then theoperation phase of the wireless power transmitter 100 will be returnedto the selection state 610.

3) Identification and Configuration State

The wireless power transmitter 100 in the identification andconfiguration state 630 may receive identification information and/orconfiguration information transmitted by the wireless power receiver200, thereby controlling power transmission to be effectively carriedout.

The wireless power receiver 200 in the identification and configurationstate 630 may transmit a power control message including its ownidentification information. For this purpose, the wireless powerreceiver 200, for instance, may transmit an identification packet 5200including a message indicating the identification information of thewireless power receiver 200 as illustrated in FIG. 16A. The packet 5200may include a header 5220 for notifying a packet indicatingidentification Information and a message 5230 including theidentification information of the electronic device. The message 5230may include information (2531 and 5232) Indicating a version of thecontract for contactiess power transfer, information 5233 foridentifying a manufacturer of the wireless power receiver 200,information 5234 indicating the presence or absence of an extendeddevice identifier, and a basic device identifier 5235. Furthermore, ifit is displayed that an extended device identifier exists in theinformation 5234 indicating the presence or absence of an extendeddevice identifier, then an extended identification packet 5300 includingthe extended device identifier as illustrated in FIG. 16B will betransmitted in a separate manner. The packet 5300 may include a header5320 for notifying a packet indicating an extended device identifier anda message 5330 including the extended device identifier. When theextended device identifier is used as described above, information basedon the manufacturer's identification information 5233, the basic deviceidentifier 5235 and the extended device identifier 5330 will be used toidentify the wireless power receiver 200.

The wireless power receiver 200 may transmit a power control messageincluding information on expected maximum power in the identificationand configuration state 630. To this end, the wireless power receiver200, for instance, may transmit a configuration packet 5400 asillustrated in FIG. 17. The packet may include a header 5420 fornotifying that it is a configuration packet and a message 5430 includinginformation on the expected maximum power. The message 5430 may includepower class 5431, information 5432 on expected maximum power, anindicator 5433 indicating a method of determining a current of a maincell at the side of the wireless power transmitter, and the number 5434of optional configuration packets. The indicator 5433 may indicatewhether or not a current of the main cell at the side of the wirelesspower transmitter is determined as specified in the contract forwireless power transfer.

On the other hand, the wireless power transmitter 100 may generate apower transfer contract which is used for power charging with thewireless power receiver 200 based on the identification informationand/or configuration information. The power transfer contract mayinclude the limits of parameters determining a power transfercharacteristic in the power transfer state 640.

The wireless power transmitter 100 may terminate the identification andconfiguration state 630 and return to the selection state 610 prior toentering the power transfer state 640. For instance, the wireless powertransmitter 100 may terminate the identification and configuration state630 to find another electronic device that can receive power in awireless manner.

4) Power Transfer State

The wireless power transmitter 100 in the power transfer state 640transmits power to the wireless power receiver 200.

The wireless power transmitter 100 may receive a power control messagefrom the wireless power receiver 200 while transferring power, andcontrol a characteristic of the power applied to the transmitting coilin response to the received power control message. For example, thepower control message used to control a characteristic of the powerapplied to the transmitting coil may be included in a control errorpacket 5500 as illustrated in FIG. 18. The packet 5500 may include aheader 5520 for notifying that it is a control error packet and amessage 5530 including a control error value. The wireless powertransmitter 100 may control the power applied to the transmitting coilaccording to the control error value. In other words, a current appliedto the transmitting coil may be controlled so as to be maintained if thecontrol error value is “0,” reduced if the control error value is anegative value, and increased if the control error value is a positivevalue.

The wireless power transmitter 100 may monitor parameters within a powertransfer contract generated based on the identification informationand/or configuration Information in the power transfer state 640. As aresult of monitoring the parameters, if power transmission to thewireless power receiver 200 violates the limits included in the powertransfer contract, then the wireless power transmitter 100 may cancelthe power transmission and return to the selection state 610.

The wireless power transmitter 100 may terminate the power transferstate 640 based on a power control message transferred from the wirelesspower receiver 200.

For example, if the charging of a battery has been completed whilecharging the battery using power transferred by the wireless powerreceiver 200, then a power control message for requesting the suspensionof wireless power transfer will be transferred to the wireless powertransmitter 100. In this case, the wireless power transmitter 100 mayreceive a message for requesting the suspension of the powertransmission, and then terminate wireless power transfer, and return tothe selection state 610.

For another example, the wireless power receiver 200 may transfer apower control message for requesting renegotiation or reconfiguration toupdate the previously generated power transfer contract. The wirelesspower receiver 200 may transfer a message for requesting therenegotiation of the power transfer contract when it is required alarger or smaller amount of power than the currently transmitted poweramount. In this case, the wireless power transmitter 100 may receive amessage for requesting the renegotiation of the power transfer contract,and then terminate contactless power transfer, and return to theidentification and configuration state 630.

To this end, a message transmitted by the wireless power receiver 200,for instance, may be an end power transfer packet 5600 as illustrated inFIG. 18. The packet 5600 may include a header 5620 for notifying that itis an end power transfer packet and a message 5630 including an endpower transfer code indicating the cause of the suspension. The endpower transfer code may indicate any one of charge complete, internalfault, over temperature, over voltage, over current, battery failure,reconfigure, no response, and unknown error.

Communication Method of Plural Electronic Devices

Hereinafter, description will be given of a method by which at least oneelectronic device performs communication with one wireless powertransmitter using wireless power signals.

FIG. 19 is a conceptual view illustrating a method of transferring powerto at least one wireless power receiver from a wireless powertransmitter.

The wireless power transmitter 100 may transmit power to one or morewireless power receivers 200 and 200′. FIG. 19 illustrates twoelectronic devices 200 and 200′, but the methods according to theexemplary embodiments disclosed herein may not be limited to the numberof electronic devices shown.

An active area and a detection area may be different according to thewireless power transfer method of the wireless power transmitter 100.Therefore, the wireless power transmitter 100 may determine whetherthere is a wireless power receiver located on the active area or thedetection area according to the resonance coupling method or a wirelesspower receiver located on the active area or the detection areaaccording to the induction coupling method. According to thedetermination result, the wireless power transmitter 100 which supportseach wireless power transfer method may change the power transfer methodfor each wireless power receiver.

In the wireless power transfer according to the exemplary embodimentsdisclosed herein, when the wireless power transmitter 100 transferspower to the one or more electronic devices 200 and 200′ according tothe same wireless power transfer method, the electronic devices 200 and200′ may perform communications through the wireless power signalswithout inter-collision.

Referring to FIG. 19, a wireless power signal 10 a generated by thewireless power transmitter 100 may arrive at the first electronic device200′ and the second electronic device 200, respectively. The first andsecond electronic devices 200′ and 200 may transmit wireless powermessages using the generated wireless power signal 10 a.

The first electronic device 200′ and the second electronic device 200may operate as wireless power receivers for receiving a wireless powersignal. The wireless power receiver in accordance with the exemplaryembodiments disclosed herein may include a power receiving unit 291′,291 to receive the generated wireless power signal, amodulation/demodulation unit 293′, 293 to modulate or demodulate thereceived wireless power signal, and a controller 292′, 292 to controleach component of the wireless power receiver.

The foregoing description has been given of the wireless powertransmission and reception method based on the WPC's standard. Inaddition, the present disclosure proposes a method in which a wirelesspower transmitter wirelessly transfers power to each of wireless powerreceivers, which comply with (support) different standards, so as to beappropriate for each standard. Furthermore, the present disclosureprovides a new type of multi-coil solution, capable of beinginteroperable with a WPC standard and a PMA standard and extending adegree of position freedom of receivers. Hereinafter, detaileddescription thereof will be given.

Method of Extending Active Area for Interoperability of DifferentStandards by Assembly of Single Coils

Hereinafter, description will be given of an active area extendingmethod in a wireless power transfer method, a wireless power transmitterand a wireless charging system, with reference to FIGS. 20 to 27. Inmore detail, description will be given of a structure of a wirelesspower transmitter, which is capable of controlling two receiverssupporting a Wireless Power Consortium (WPC) standard and a PowerMatters Alliance (PMA) standard in a manner of assembling single coils,and a coil controlling method.

WPC and PMA standards are standards which are the most widely used inrecent time among magnetic induction type wireless charging standards.The WPC and PMA standards are the same in basic principle but differentin frequency. The WPC standard generally employs a coil method, whereasthe PMA standard generally uses a method of forming a pattern in aspiral coil shape by etching a printed circuit board (PCB).

However, a problem is caused in that these two types of inductivewireless charging standards are not interoperable with each other.Therefore, there is not a single type coil which simultaneously meetstwo different standards. Here, the PMA which has been established laterhas a coil standard similar to the WPC. The present disclosure providesa multi-coil solution using such similar coil standard. That is, thepresent disclosure proposes a multi-coil structure for a transmitter,which is interoperable with a WPC-complaint receiver and a PMA-complaintreceiver.

FIGS. 20 and 21 are a planar view and a front view respectivelyillustrating a transmission unit of a transmitter with an assembly ofsingle coils, FIGS. 22A and 22B are a planar view and a front view of afirst type coil illustrated in FIG. 20, FIGS. 23A and 23B are a planarview and a front view of a second type coil illustrated in FIG. 20, andFIGS. 24A and 24B are front views illustrating an exemplary variation ofthe transmitter of FIG. 21.

As illustrated in FIGS. 20 and 21, a wireless power transmitter mayinclude a first coil 3111, a second coil 3112, and a third coil 3120.

The first coil 3111 is a coil for converting a current into a magneticflux, and may be wound into a quadrilateral shape in which at least partis straight (linear). As one example, the first coil 3111 may be a coilwound into a rectangular (or square) shape. The second coil 3112 may beadjacent to the first coil 3111 on a plane, and have the same shape asthe first coil 3111. Also, the first coil 3111 and the second coil 3112may be disposed on the same plane.

In more detail, the second coil 3112 may be a coil which is wound into arectangular shape, as the same as the first coil 3111. The first coil3111 and the second coil 3112 are the same type of coil, but the thirdcoil 3120 has a different shape from the first coil 3111 and the secondcoil 3112. Therefore, the third coil 3120 may be referred to as a firsttype coil and the first coil 3111 and the second coil 3112 may bereferred to as second type coils.

As illustrated in FIGS. 22A and 22B, the second type coils may consistof a single layer. For example, the second type coils may be wound intoa rectangular shape and form a single layer on a plane. As such example,the second type coil may be a coil compliant with the WPC standard.

In more detail, the second type coil may be a wire-wound type andconsist of no. 17 AWG (1.15 mm diameter) type 2 litz wire having 105strands of no. 40 AWG (0.08 mm diameter). The second type coil may be acoil that such wire is wound into a rectangular shape according toWPC-compliant A6 or A13 and consists of a single layer.

The second type coil may include a central area 3113 which is an emptyspace without a coil formed therein, and a coil area 3114 which isformed along an outer circumference of the central area 3113 and woundwith a coil.

For example, an outer length of the coil (i.e., a length of an outerbase of a rectangle) may be 53.2±0.5 mm, an outer width (i.e., a lengthof an outer side of the rectangle) may be 45.2±0.5 mm, an inner length(i.e., a length of a base of the central area) may be 27.5±0.5 mm, andan inner width (i.e., a length of a side of the central area) may be19.5±0.5 mm. Also, a thickness of the coil may be 1.5±0.5 mm, and thewire may be wound 12 times on the single layer.

Referring back to FIGS. 20 and 21, the third coil 3120 may be arrangedsuch that at least part thereof overlaps the first coil 3111 and thesecond coil 3112, respectively. In more detail, the third coil 3120 maybe arranged such that a center thereof is located between the first coil3111 and the second coil 3112 to overlap both of the coils.

In this case, an outer side of the first coil 3111 and an outer side ofthe second coil 3112 may be arranged in parallel to each other. Also,the first coil 3111 and the second coil 3112 may be formed such thatouter sides of the rectangular shapes come in contact with each other.The third coil 3120 may be arranged between centers of the first coil3111 and the second coil 3112. For example, the assembly of the firstcoil 3111, the second coil 3112 and the third coil 3120 may have asymmetrical shape based on the center of the third coil 3120. Accordingto the structure, an overlapped size between the third coil 3120 and thefirst coil 3111 may be the same as an overlapped size between the thirdcoil 3120 and the second coil 3112.

The assembly of the coils disclosed herein may be a multi-coil that thefirst type coil and the second type coils overlap each other.

As illustrated in FIGS. 23A and 23B, the first type coil may be formedto have a plurality of layers. For example, the first type coil may bewound into a circular shape and consist of multiple layers. As oneexample, the first type coil may be a coil compliant with the WPCstandard.

In more detail, the first type coil may be a wire-wound type, andconsist of no. 17 AWG (1.15 mm diameter) type 2 litz wire having 105strands of no. 40 AWG (0.08 mm diameter), as the same as the second typecoil. For example, the first type coil may be a wire-wound type andconsist of no. 17 AWG (1.15 mm diameter) type 2 litz wire having 105strands of no. 40 AWG (0.08 mm diameter), according to a WPC-compliantA1 or A17. The first type coil may be a coil that such wire is woundinto a circular shape and consists of a plurality of layers. To form aplurality of layers, the first type coil may be connected at an innerside thereof and wound into two layers.

As illustrated, the first type coil may include a central area 3123which is an empty space without a coil formed therein, and a coil area3124 formed along an outer circumference of the central area 3123 andwound with a coil. The coil area 3124 may be made of a winding coilwhich is warped (a shape of a Greek alphabet ‘α’) into two layers, andthe central area 3123 may be empty. However, the present disclosure maynot be limited to this. The first type coil may be implemented into ashape stacked on the PCB into two layers, and a magnet may be disposedin the central area 3123.

An outer diameter of the coil (i.e., a diameter of an outer circle), forexample, may be 43±0.5 mm, and an inner diameter (i.e., a diameter ofthe central area) may be 20.5±0.5 mm. Also, a thickness of the coil maybe 2.1±0.5 mm, and the wire may be wound 10 times per one layer to formtwo layers.

In such a manner, the first type coil may be formed similar to aPMA-compliant coil. It can thusly be understood that the third coil 3120is a coil which complies with (or supports) both the WPC and PMAstandards. The present disclosure uses the first type coil as a coilinteroperable with the WPC and PMA standards.

Referring back to FIGS. 20 and 21, the first coil 3111 and the secondcoil 3112 may be stacked on one surface of the third coil 3120. That is,the first type coil may be arranged beneath the second type coils.

Since the first type coil is made by winding a wire of the samethickness into two layers, it may be thicker than a rectangular coilwound into a single layer. A distance from a transmitting coil to asurface of a charger is generally limited to 3 mm. Therefore, as astructural method for overlapping a charging area, the thick first typecoil may be disposed beneath the second type coils so as to maintain thedistance from the transmitting coil to the surface. Also, in order tooverlap the first type coil without separation of the charging area, thesecond type coils may be formed in the rectangular shape. Specifically,only when inner regions of the coils are fully overlapped, the chargingarea is not separated. Therefore, this exemplary embodiment illustratesthat the rectangular coils are adjacent to each other and a center ofthe circular coil is disposed at a boundary between the rectangularcoils.

As illustrated, a shielding member 3130 may be disposed on the othersurface (an opposite surface to the surface on which the first andsecond coils are disposed) of the third coil 3120. That is, theshielding member 3130 may be disposed beneath the first type coil.

The shielding member 3130 may be disposed more adjacent to the thirdcoil 3120 than the first coil 3111 and the second coil 3112 so as toprevent a generated magnetic field from being transferred to a basestation.

In this case, the base station may be a body of a portable electronicdevice, a charging cradle of a vehicle, and the like. The base stationis a device which can provide near field inductive power, and may havean active area. The active area may be a part of an interface surface ofthe base station, through which a magnetic flux flows, when the basestation supplies power to the portable electronic device or the chargingcradle. In this case, a distance from the transmitting coil (the firstcoil, the second coil and the third coil) to one surface (the interfacesurface) of the base station may be 3.0±0.5 mm.

The shielding member 3130 may protect devices (for example, amicroprocessor) mounted on a PCB from an electromagnetic affectioncaused due to an operation of the transmitting coil, or protect thetransmitting coil from an electromagnetic affection caused due tooperations of the devices mounted on the PCB.

The shielding member 3130 may overlap the transmitting coil. Forexample, the shielding member 3130 may be formed between a case of thebase station and the transmitting coil.

The shielding member 3130 may be formed such that at least part thereofexceeds an outer diameter of an outer circle of the third coil. Forexample, the shielding member 3130 may extend from the outer diameter ofthe outer circle by at least 2 mm, and be disposed beneath the thirdcoil by a distance of 1.0 mm in maximum.

According to the structure, the rectangular coil which is spaced apartfrom the shielding member, as compared with the circular coil which isadhered right on the shielding member, may have a reduced inductance.Therefore, the structure of this embodiment may be varied as illustratedin FIGS. 24A and 24B. FIGS. 24A and 24B are a planar view and a frontview illustrating an exemplary variation of the transmitter of FIG. 21.

As illustrated in FIGS. 24A and 24B, an auxiliary shielding member 3140may be disposed between the first coil 3111 and the second coil 3112 andthe shielding member 3130.

The auxiliary shielding member 3140 may provide a 2-layer shieldingstructure such that different types of coils (the first type coil andthe second type coils) have standard-compliant inductances,respectively. The auxiliary shielding member 3140 may include first andsecond auxiliary shielding members 3141 and 3142. The first and secondauxiliary shielding members 3141 and 3142 may be disposed adjacent toeach other on the same plane. The first and second auxiliary shieldingmembers 3141 and 3142 may be made of the same material in the sameshape. Also, the first and second auxiliary shielding members 3141 and3142 may be provided, respectively, with a first groove 3141 a and asecond groove 3142 a which are semicircular to correspond to thecircular shape of the third coil 3120. In this case, detailed designnumerical values of the first and second auxiliary shielding member 3141and 3142 may be decided according to an experiment such that the firsttype coil and the second type coils have inductances compliant withstandards, respectively.

The multi-coil solution disclosed herein may use the assembly of thesingle coils, which complies with (or supports) the two differentstandards. Accordingly, the multi-coil solution may allow for using(supporting) both of two standards of the receiver and extending theactive area.

In addition, the present disclosure may be configured to operate thewireless power transmitter in such a manner that a controller detects astandard applied to the receiver, and determines a coil to be drivenamong the first coil, the second coil, and the third coil using thedetected standard. Hereinafter, the operating method will be describedin more detail.

FIG. 25 is a flowchart illustrating a method for driving (operating) atransmitter, and FIG. 26 is a detailed flowchart illustrating oneembodiment of the operating method of FIG. 25.

According to the operating method, a controller of a transmitter mayapply an input voltage to at least one of the first, second and thirdcoils (S3110). In this case, the applied input voltage may be 12V. Next,the controller may detect a standard which a wireless power receivercomplies with (or supports), in correspondence with the input voltage(S3120). The detection of the standard may be carried out by thecontroller of the transmitter through communication with the receiveraccording to a WPC or PMA communication standard.

Here, the controller may detect a coil to be driven from the first,second and third coils if the standard is a first standard, and drivethe third coil if the standard is a second standard. (S3130). In thiscase, the first standard may be a WPC standard and the second standardmay be a PMA standard. However, the present disclosure may not belimited to this. The first and second standards may be other standardsexcept for the WPC and PMA standards.

In addition, if the standard is the first standard, then the controllermay detect whether the coil to be driven is a coil wound into aquadrilateral shape or a coil wound into a circular shape in compliancewith the first standard (S3140). In more detail, if the standard is thefirst standard, the controller may detect whether the coil to be drivenis a WPC-compliant A6 or A13 coil or a WPC-compliant A17 coil.Afterwards, the controller may control one of the first, second andthird coils to transfer power in a wireless manner according to thedetection result.

In this case, since the third coil is the coil which is interoperablewith the first standard or the second standard, the controller mayselectively apply one of a plurality of voltages to the third coil. Inmore detail, the controller may apply a voltage corresponding to a sizeof an input voltage to at least one of the first, second and thirdcoils. After detecting the standard, the controller may boost ormaintain the input voltage to be compliant with the standard.

For example, if the standard is the first standard, the controller maydetermine one coil to control from the first, second and third coils. Ifthe standard is the second standard, the controller may boost the inputvoltage applied to the third coil and carry out a frequency control.

In this case, it may be set that the first coil and the second coil arecoils to which the input voltage Is applied and a voltage higher thanthe input voltage is applied to the third coil under the first standard.Also, the first coil and the second coil may be coils for which afrequency control or a voltage control is carried out under the firststandard, and the third coil may be a coil for which the voltage controlis carried out under the first standard. For example, the first, secondand third coils may be the coils named equally as described withreference to FIGS. 20 to 24B.

Hereinafter, the operating method will be described in more detail, withreference to FIG. 26.

First, the controller may apply an input voltage of 12V to a coil todetect whether the receiver supports the first standard. If a signalcompliant with the first standard sent from the receiver has not beenreceived, the controller may determine that the receiver supports thesecond standard. Afterwards, the controller may boost the voltageapplied to the first type coil into a voltage higher than the inputvoltage. For example, the controller may boost the input voltage into19V and thereafter transfer power in a wireless manner through thefrequency control. In such a manner, the controller may boost the inputvoltage and carry out the frequency control when the detected standardis the second standard.

On the other hand, if the signal compliant with the first standard isreceived from the receiver, the controller may determine whether thecoil of the receiver is the first type coil or the second type coil. Thedetermination may be made according to a communication protocol of thefirst standard.

If the coil of the receiver is the first type coil, the controller maydetermine the coil of the receiver is the coil which is wound into acircular shape in compliance with the first standard and thereafterboost the voltage applied to the first type coil into a voltage higherthan the input voltage. The coil wound into the circular shape may bethe WPC-compliant A1 or A17 coil, for example. As one example, thevoltage applied to the third coil may be 15V, and power may bewirelessly transferred through the voltage control (voltage &frequency).

In this case, if the coil of the receiver is the second type coil, thecontroller may determine which one of the coils wound into therectangular shape in compliance with the first standard corresponds tothe coil of the receiver. The coil wound into the circular shape may bethe WPC-compliant A6 or A13 coil, for example. If a coil to be driven isthe A17 coil, the controller may boost the input voltage. If the coil tobe driven is the A6 or A13 coil, the controller may maintain the inputvoltage. For example, while maintaining the size of the input voltage,the controller may carry out the frequency control (or a frequency &duty cycle control) with respect to at least one of the first and secondcoils when the coil is determined as the WPC-compliant A6, and carry outthe voltage control (or a voltage & frequency control) when the coil isdetermined as the WPC-compliant A13 of the standard.

As such, in a manner that an operation voltage of the first type coilwhich is interoperable with the WPC and PMA standards is higher thanthat of the second type coil which is dedicated for the WPC standard,the standard of the receiver can be detected by a low voltage.

According to the foregoing processes, an operating method for atransmitter which is operated to be interoperable with a plurality ofstandards may be implemented by using the multi-coil structure describedwith reference to FIGS. 20 to 24B.

Hereinafter, description will be given of a circuitry construction whichcan support the operating method for the transmitter. FIG. 27 is astructural view of a circuit implementing the operating method of FIG.26.

As illustrated in FIGS. 20 to 24B, the coil wound into the circularshape in compliance with the first standard is employed as the firsttype coil which is a center coil, and the coil wound into therectangular shape appropriate for an input voltage of 12V is employed asthe second type coil which is both of side coils. For example, the firsttype coil as the center coil may be the WPC-compliant A17 coil, and thesecond type coil as the side coils may be the A6 or A13 coilsappropriate for the input voltage of 12V.

With respect to the input voltage of 12V for operating the coils, thecontroller may decide a control method according to which receiver (aPMA-compliant receiver or a WPC-compliant receiver) is placed on whichcoil. In this case, the controller may be implemented as a type ofmicrocomputer (or a micro controller unit (MCU)).

For example, for the first type coil, a size of a voltage may be changedfrom 15V into 19V in a manner of executing a boost control for a voltageboost block. In this case, the voltage size by the voltage control maybe adjusted according to a DA value of the MCU through Vrail control.

A PMA-compliant operation may serve to switch a frequency when the firsttype coil is operated as a PMA coil (for example, PMA 2) or the secondtype coil is operated as a WPC A6 coil.

As illustrated, the controller may control a driving circuit unit. Thedriving circuit unit may include a first switch SW1 connected to a firstcapacitor C1, and a second switch SW2 connected to a second capacitorC2. The first capacitor C1 and the second capacitor C2 may be connectedto the first type coil (or the third coil) in parallel. The first andsecond switches SW1 and SW2 may be controlled to apply one of aplurality of voltages to the first type coil (or the third coil)according to whether the standard is the WPC standard or the PMAstandard.

If the receiver supports the WPC standard, the first switch SW1 may beturned on (dosed) and the second switch SW2 may be turned off (opened)such that the first capacitor C1 is electrically connected to the firsttype coil (or the third coil). In this case, the first capacitor C1 maybe configured to correspond to a circuit standard of the WPC-compliantA17 coil.

The A17 coil may be configured such that an operating frequency thereofis f=105 to 116 kHz with a duty cycle of 50%, the total serialcapacitance in a configuration of a full-bridge inverter is C=100±5% nF,and parallel capacitance is C=200±5% nF. The regulation of thecapacitance is different from the PMA regulation. This exemplaryembodiment may provide a circuit view of varying capacitance.

As illustrated, if the receiver supports the PMA standard, the firstswitch SW1 may be turned off (opened) and the second switch SW2 may beturned on (dosed) such that the second capacitor C2 is electricallyconnected to the first type coil (or the third coil). In this case, thesecond capacitor C2 may be configured to correspond to the PMA-compliantcoil.

According to the circuit configuration, all of the three coils maysupport the WPC-compliant receiver, and the center coil may support thePMA-compliant receiver.

Hereinafter, description will be given of another structure of atransmitter which can transfer power in a wireless manner to everyreceiver compliant with two different standards.

The present disclosure may provide a transmitter which is capable ofwirelessly transmitting power in a manner of controlling a transmitterto support (or be appropriate for) a resonant frequency of thetransmitter and two different standards. In more detail, the presentdisclosure provides a wireless power transmitter allowed for a frequencyconversion using the point that most regulations are the same or similarbut frequency bands used are different in view of the WPC and PMAstandards.

FIGS. 28 and 29 are a block diagram of a wireless power transmitter, anda flowchart illustrating a method of operating the transmitter totransmit power in a wireless manner to a receiver supporting twodifferent standards, FIG. 30 is a conceptual view illustrating a coiluseable in a wireless power transmitter, and FIG. 31 is a structuralview of a circuit implementing a method by which a wireless powertransmitter transmits power in a wireless manner to be compliant with(be appropriate for, support, or be interoperable with) differentstandards.

Hereinafter, description will be given of a method of transferring powerin a wireless manner by a wireless power transmitter.

First, a transmitter disclosed herein may generate signals complyingwith different standards in a sequential manner, in order to detect astandard that a receiver supports (S2910). Here, the signals may besequentially generated in an alternating manner with preset intervals.

In more detail, the transmitter disclosed herein may sequentiallygenerate a first signal compliant with the WPC standard and a secondsignal compliant with the PMA standard in an alternating manner.

Afterwards, the transmitter may detect a communication standard that thereceiver supports, using a receiver's response to one of the generatedsignals (S2920).

In more detail, if the receiver receives a signal which is appropriatefor its standard among the signals generated by the transmitter, thereceiver may transmit a power control message. The power control messagemay be information including at least one characteristic of frequency,voltage and current by which the transmitter operates. Here, thetransmitter which has received the power control message may detect thestandard that the receiver supports, based on the information includedin the power control message.

When the receiver's standard is detected, the transmitter may control anelectric connection of a plurality of capacitors included in a circuitunit 130 such that power can be wirelessly transferred according to thedetected standard (S2930).

In more detail, since the WPC communication standard and the PMAcommunication standard use different frequency bands from each other,the transmitter may change its operating frequency band such that thedifferent standards can be supported. That is, the WPC communicationstandard uses a frequency band in the range of 105 to 205 kHz, and thePMA communication standard uses a frequency band in the range of 227 to278 kHz.

Here, an assembly of a plurality of capacitors may be used to change theoperating frequency band without a change of a power transfer unit 110(for example, a coil).

For example, when the WPC communication standard is detected, thecontroller 140 may control the electric connection of the plurality ofcapacitors such that the assembly of the plurality of capacitors is 200nF. Also, when the PMA communication standard is detected, thecontroller 140 may control the electric connection of the plurality ofcapacitors such that the assembly of the plurality of capacitors is 55nF.

Here, the assembly of the plurality of capacitors may be changed usingat least one switch which is connected to at least some of the pluralityof capacitors. For example, the circuit unit 130 may include a firstcapacitor and a second capacitor. The first and second capacitors may beconnected in parallel to each other, and a switch may be additionallyconnected to the second capacitor. Here, the controller 140 may change acapacitor value of the circuit unit 130 by turning on/off the switch.

In more detail, the controller 180 may turn on the switch when thecommunication standard is the WPC communication standard, and may notturn on the switch when the communication standard is the PMAcommunication standard.

When the standard that the receiver supports is detected, the controllermay boost an input voltage or depressurize an input voltage of thetransmitter such that the communication standard can be supported. Inmore detail, when the PMA communication standard is detected, thecontroller 140 may boost or depressurize the input voltage of thetransmitter to be set into 18V. Similar to this, when the WPC standardis detected, the controller 140 may boost or depressurize the inputvoltage to be set to 12V.

Along with this, when the standard that the receiver supports isdetected, the controller 140 may control an operating topology (forexample, a communication block) of the transmitter such that thecommunication standard can be supported. In more detail, the control ofthe operating topology may be carried out in a manner of adjusting acut-off frequency of a low pass filter. For example, the controller mayadjust the cut-off frequency down to less than 5 kHz when the WPCcommunication standard is detected, and adjust the cut-off frequencydown to less than 20 kHz when the PMA standard is detected.

Also, the wireless power transmitter for transferring power in thewireless manner may include at least one of a voltage supply unit 110 tosupply a voltage, a power transfer unit 120 having at least one coil totransfer power by converting a current into a magnetic field, a circuitunit 130 connected to the power transfer unit 120 in series and having aplurality of capacitors for converting a frequency of the transmitter,and a controller 140 to control the voltage supply unit 110, the powertransfer unit 120, and the circuit unit 130 to be appropriate for thestandard of the receiver. In addition, the transmitter disclosed hereinmay further include a communication block (not illustrated).

The voltage supply unit 110 may supply power to be used by the circuitunit 130, the power transfer unit 120 and the controller 140. Thevoltage supply unit 110 may also supply an input voltage to beappropriate for different wireless power standards through the controlof the controller 140.

The controller 140 may be implemented as a type of microcomputer (ormicro controller unit (MCU)) which is formed on a PCB mounted on aportable electronic device or a charging cradle.

The controller 140 may control the power transfer unit 120 to transferpower to the receiver.

The power transfer unit 120 may include at least one coil for convertinga current into a magnetic flux. The at least one coil may be a differenttype of coil or the same type of coil. Also, the at least one coil mayhave the same shape or a different shape. For example, the at least onecoil may be a coil wound to form the same rectangular shape.

The at least one coil may also be disposed on a plane to be adjacent toeach other. For example, the at least one coil may be disposed such thatat least part thereof overlaps each other.

Also, the at least one coil may be activated in all or in part. That is,the at least one coil may be partially activated to transfer power in awireless manner. Here, the activation of the coils indicates that thecoil becomes a state in which a current transferred from the powersupply unit can be converted into a magnetic field.

Here, a selection of a coil to activate may be decided based onreception or non-reception of an enable signal. The controller 140 mayactivate the coil in a manner of transmitting the enable signal to acoil to activate among the at least one coil. In this case, power may betransferred to the wireless power receiver through the activated coil.

Here, the controller 140 may decide a coil to receive the enable signalaccording to receiver-related position information included in a powertransfer message, received from the receiver. For example, thecontroller 140 may activate a coil which is located at an area adjacentto the receiver.

In one exemplary embodiment of a coil usable in the present disclosure,the WPC-compliant A13 coil may be used. The A13 coil may be a wire-woundtype and consist of no. 17 AWG (1.15 mm diameter) type 2 litz wirehaving 105 strands of no. 40 AWG (0.08 mm diameter). The A13 coil mayhave a rectangular shape and consist of a single layer.

Referring to (a) of FIG. 30, an outer length dol of the A13 coil (alength of an outer base of a rectangle) may be 53.2±0.5 mm, an outerwidth dow (a length of an outer side of the rectangle) may be 45.2±0.5mm, an inner length dil (a length of a base of a central area) may be27.5±0.5 mm, and an inner width diw (a length of a side of the centralarea) may be 19.5±0.5 mm. Also, a thickness of the coil may be 1.5±0.5mm, and the wire may be wound 12 times on the single layer.

Referring to (b) of FIG. 30, the A13 coil may be arranged such that atleast part of each of a plurality of coils overlaps each other.Odd-numbered coils may be disposed to overlap each other with a distancedoo of 49.2±4 mm between centers of the coils. Also, an even-numberedcoil may be disposed to be orthogonal to the odd-numbered coils andoverlap the odd-numbered coils with a distance doe of 24.6±2 mm betweencenters of the even-numbered coil and the odd-numbered coil. The presentdisclosure may dispose the coils in the overlapping manner so as tofully prevent a charging area from being separated.

The controller 140 may change the operating frequency band of thetransmitter so as to support the receiver's communication standard whenthe receiver's standard is detected. Here, the controller may controlthe electric connection of the plurality of capacitors constructing thecircuit unit 130 for changing the operating frequency band.

In more detail, the circuit unit 130 may include a plurality ofcapacitors and at least one switch. Here, the controller 140 may changean assembly of the plurality of capacitors so as to adjust a capacitorvalue of the circuit unit 130.

Also, the circuit unit 130 may be electrically connected to the powertransfer unit 120. In more detail, the circuit unit 130 may be connectedto the power transfer unit 120 in series. That is, the power transferunit 120 may share the plurality of capacitors constructing the circuitunit 130.

The plurality of capacitors may be connected in parallel. In moredetail, the plurality of capacitors may include a first capacitor and asecond capacitor. Here, the second capacitor may be connected inparallel to the first capacitor.

A switch may be connected to at least part of the plurality ofcapacitors of the circuit unit 130 in order to change the assembly ofthe plurality of capacitors. The controller 140 may change the assemblyof the plurality of capacitors by turning on/off the switch. In otherwords, the controller 140 may decide the number of capacitors to be usedfor wireless power transfer among the plurality of capacitors, and turnon/off the switch to correspond to the number. In more detail, thecontroller 140 may turn on the switch when the detected communicationstandard is the WPC communication standard, and turn off the switch whenthe detected communication standard is the PMA communication standard.

The controller 140 may control operations of the power supply unit 110,the power transfer unit 120 and the circuit unit 130.

The controller 140 may control the power supply unit 110 to supply powerto the power transfer unit 120. Also, the controller 140 may decide acoil to be activated among the at least one coil constructing the powertransfer unit 120. Also, the controller 140 may decide the number ofcapacitors to be used for wireless power transfer among the plurality ofcapacitors constructing the circuit unit 130.

Here, the controller 140 may decide the number of capacitors to be usedfor the wireless power transfer according to a communication standard tobe used for communication. For example, when communication is carriedout according to the WPC communication standard, the controller 140 maydecide the number of capacitors to have capacitance appropriate for thePWC communication standard. When communication is carried out accordingto the PMA communication standard, the controller 140 may decide thenumber of capacitors to have capacitance appropriate for the PMAcommunication standard.

The communication block (not illustrated) may include a low pass filterconfigured to change a cut-off frequency such that communication can becarried out. Here, the controller 140 may control the communicationblock such that the cut-off frequency can be compliant with eachcommunication standard. An analog demodulator may be used as an exampleof the communication block. The analog demodulator may be implemented asa low pass filter.

When the receiver's communication standard is detected, the analogdemodulator may transmit a signal to the controller 140 such that thecut-off frequency can be changed according to the detected communicationstandard. In this case, the controller 140 may change the cut-offfrequency of the analog demodulator.

Meanwhile, the communication block may be provided in plurality forsupporting each communication standard. Here, the controller 140 mayexecute communication by activating a communication block which supportsa detected communication standard among the plurality of communicationblocks.

FIG. 32 is a graph illustrating an example that communications compliantwith the two communication standards (WPC and PMA) are actually executedusing a circuit in which a resonant frequency is decided based on thenumber of capacitors.

First, a test may be carried out under a condition having a small loadas illustrated in (a) of FIG. 32, and under a condition having a largeload as illustrated in (b) of FIG. 32.

Here, as illustrated in (a) and (b) of FIG. 32, it can be noticed thatthe PMA and WPC communications are smoothly carried out in both of theconditions having the small and large loads.

The controller 140 may generate a detection signal compliant with eachcommunication standard in a sequential manner so as to detect acommunication standard that the wireless power receiver supports. Inmore detail, the controller 140 may generate a first signal compliantwith the WPC communication standard and a second signal compliant withthe PMA communication standard in a sequential manner.

Here, the generating of the first signal may be referred to as “analogping” and the generating of the second signal may be referred to as“active ping.” The first signal may transmit a signal of 113 kHz band.Also, the second signal may transmit a signal of 210 kHz band.

The signals may be sequentially generated with a preset interval withrespect to each coil. In more detail, the controller 140 may generatethe first signal and the second signal in an alternating manner, therebydetecting the communication standard that the wireless power receiversupports.

The foregoing description has been given of the method of detecting thecommunication standard of the receiver, and controlling the frequencyband, the operating topology and the input voltage of the transmitter towirelessly transfer power according to the detected communicationstandard. Consequently, a transmitter which is capable of transferringpower to receivers complying with different standards can beimplemented.

Hereinafter, description will be given in more detail of a method ofdetecting a communication standard by a wireless power transmitter, withreference to FIG. 33.

When a communication standard that the wireless power receiver supportsis detected, the controller 140 may control an operation of at least oneof the circuit unit 130 and the voltage supply unit 110 to wirelesslytransfer power according to the communication standard.

In more detail, referring to FIG. 33, the controller 140 may select acoil to be activated from a plurality of coils constructing the powertransfer unit 120 (S3310). Here, the coil to be activated may be decidedbased on position information related to the receiver. For example, thecontroller 140 may transmit an enable signal to a coil located at anarea adjacent to the position of the receiver and activate the coil.

Afterwards, the controller 140 may control the circuit unit to bechanged into a communication state under the WPC communication standardfor transmitting a WPC-compliant frequency to the activated coil(S3320). For example, the controller 140 may set a capacitance value ofthe circuit unit 130 to 200 nF, and change an operating topology and aninput voltage.

After the change, the controller 140 may detect whether or not thereceiver supports the WPC communication standard (S3330). If it isdetected that the receiver supports the WPC communication standard, thecontroller 140 may perform WPC charging (S3340).

However, if the receiver does not support the WPC communicationstandard, the controller 140 may control the power transfer unit 120 andthe circuit unit 130 for enabling the communication under the PMAcommunication standard (S3350). For example, the controller 140 may seta capacitance value of the circuit unit 130 to 55 nF, activate a PMAcommunication unit, and change an operating topology and an inputvoltage (S3350).

After the change, the controller 140 may detect whether or not thereceiver supports the PMA communication standard (S3360). If thereceiver is detected as supporting the PMA communication standard, thecontroller 140 may carry out PMA charging (S3370).

FIG. 34 is a graph illustrating test results according to methods ofdetecting the WPC and PMA communication standards. As illustrated inFIG. 34, a wireless power transmitter disclosed herein may transmitdifferent signals complying with different communication standards to aplurality of coils with a preset time interval, respectively.

Here, when a response to one of the signals is received, the wirelesspower transmitter may control the circuit unit 130 to have a capacitancevalue which is defined in the communication standard according to thesignal. That is, the controller 140 may change a frequency value tosupport the communication standard compliant with the signal.

For example, (a) of FIG. 34 illustrates that communication is actuallysmoothly carried out after controlling the capacitance value to beappropriate for the PMA standard. (b) of FIG. 34 illustrates thatcommunication is actually smoothly carried out after controlling thecapacitance value to be appropriate for the WPC standard.

FIG. 35 is a structural view illustrating another type of circuit viewin a wireless power transmitter according to one exemplary embodimentdisclosed herein.

The aforementioned circuit view has the structure in which a switch isconnected to one of two capacitors and a frequency is controlled byturning on/off the switch according to a communication standard. Inaddition to the structure, the present disclosure may have a structurein which a switch is connected to each capacitor to decide which one ofthe two capacitors is to be used according to a communication standard.

In this case, the controller 140 may change a frequency by controllingfirst and second switches according to a detected communicationstandard. Also, even in the structure, all of the other operationsexcept for the addition of the first and second switches may be the sameas those in the foregoing description.

As described above, a wireless power transmitter disclosed herein may beallowed to use an assembly of single coils compliant with two differentstandards, as a multi-coil, so as to be interoperable with everystandard even if the coil of the receiver supports any standard.

The present disclosure may implement a wireless power transmittingmethod, a wireless power and a wireless charging system, which arecapable of wirelessly transmitting power of standards corresponding toreceivers which support different standards, through a multi-coilsolution.

Also, the present disclosure may provide a multi-coil solution which canimplement a transmitter, which complies with two different standardsusing a single coil, in a manner of overlapping a pair of coils withanother coil with a different shape. Also, the overlapped coils may beconfigured to support two different standards, thereby extending activeareas of a wireless power transmitter, a wireless power receiver, and awireless charging system. That is, a multi-coil, namely, an assembly ofsingle coils complying with two different standards may be used for thewireless power transmitter, such that the transmitter can support astandard even if the coil of the receiver complies with any standard.

The present disclosure may also provide a transmitter havinginteroperability between different standards in a manner of changing aresonant frequency of the transmitter with respect to receiverssupporting different standards. This may allow the transmitter totransfer power in a wireless manner, irrespective of a communicationstandard of a receiver.

However, it would be easily understood by those skilled in the art thatthe configuration of a wireless power transmitter according to theembodiment disclosed herein may be applicable to an apparatus, such as adocking station, a terminal cradle device, and an electronic device, andthe like, excluding a case where it is applicable to only a wirelesscharger.

The scope of the invention will not be limited to the embodimentsdisclosed herein, and thus various modifications, variations, andimprovements can be made in the present invention without departing fromthe spirit of the invention, and within the scope of the appendedclaims.

What is claimed is:
 1. A wireless power transmitter configured totransfer power to a wireless power receiver in a wireless manner, thetransmitter comprising: a power transfer unit configured to transmitpower to the wireless power receiver in the wireless manner; a circuitunit having a plurality of capacitors electrically connected to thepower transfer unit, and configured to support each of a plurality offrequencies by changing the electric connection of the capacitors; and acontroller configured to detect a communication standard which thewireless power receiver complies with, and control the electricconnection of the capacitors such that the circuit unit operates at afrequency corresponding to the detected communication standard.
 2. Thewireless power transmitter of claim 1, wherein the circuit unit variesthe number of capacitors included in a resonant circuit for transmittingpower in the wireless manner among the plurality of capacitors.
 3. Thewireless power transmitter of claim 2, wherein the circuit unitcomprises: a first capacitor electrically connected to the powertransfer unit; a second capacitor connected to the first capacitor inparallel; and a switch connected to the second capacitor, wherein thecontroller controls the electric connection of the second capacitorusing the switch.
 4. The wireless power transmitter of claim 3, whereinthe controller turns on the switch when the detected communicationstandard is a Wireless Power Consortium (WPC) communication standard,and turns off the switch when the detected communication standard is aPower Matters Alliance (PMA) communication standard.
 5. The wirelesspower transmitter of claim 1, wherein the controller generates signalscomplying with different communication standards in a sequential manner,to detect a communication standard that the wireless power receiversupports.
 6. The wireless power transmitter of claim 5, wherein thesignals comprise a first signal complying with a first communicationstandard, and a second signal complying with a second communicationstandard, wherein the controller decides whether the wireless powerreceiver supports the first communication standard or the secondcommunication standard using a response of the wireless power receiverto one of the first and second signals.
 7. The wireless powertransmitter of claim 6, wherein the controller controls the electricconnection of the plurality of capacitors such that the circuit unitoperates in a frequency range corresponding to the decided onecommunication standard when the one communication standard is decided.8. The wireless power transmitter of claim 6, wherein the controllerboosts or depressurizes an input voltage such that the circuit unit cansupport the decided one communication standard when the onecommunication standard is decided.
 9. The wireless power transmitter ofclaim 8, wherein the controller carries out one of a frequency controland a voltage control with respect to the power transfer unit based onthe decided one communication standard when the one communicationstandard is decided.
 10. The wireless power transmitter of claim 2,wherein the circuit unit comprises a first switch connected to a firstcapacitor, and a second switch connected to a second capacitor, whereinthe first capacitor and the second capacitor are connected in parallel,and wherein the controller controls an electric connection of the secondcapacitor using the first and second switches.
 11. The wireless powertransmitter of claim 10, wherein the controller controls the first andsecond switches such that both of the first and second capacitors areelectrically connected to the power transfer unit when the communicationstandard complies with the WPC, and wherein the controller controls thefirst and second switches such that one of the first and secondcapacitors is electrically connected to the power transfer unit when thecommunication standard complies with the PMA.
 12. The wireless powertransmitter of claim 1, wherein the power transfer unit is aWPC-compliant A13 coil for which a frequency control or a voltagecontrol is carried out.
 13. A wireless power transfer method configuredto transmit power to a wireless power receiver in a wireless manner, themethod comprising: generating a first signal complying with a firstcommunication standard and a second signal complying with a secondcommunication standard in a sequential manner, so as to detect acommunication standard that the wireless power receiver supports;determining a communication standard that the wireless power receiversupports from the first and second communication standards, using aresponse of the receiver to one of the first and second signals; andcontrolling an electric connection of a plurality of capacitors suchthat power is transferred in the wireless manner at one of a pluralityof frequency bands according to the determined communication standard.14. The method of claim 13, wherein the controlling of the electricconnection of the capacitors is performed to decide the number ofcapacitors to be used in a resonant circuit compliant with thedetermined communication standard.
 15. The method of claim 14, wherein afirst capacitor and a second capacitor are provided, wherein a switch isconnected to the second capacitor, and wherein the controlling of theelectric connection of the capacitors is performed to turn on the switchwhen the determined communication standard is the WPC communicationstandard.
 16. The method of claim 13, further comprising boosting ordepressurizing an input voltage according to the determinedcommunication standard.
 17. A wireless charging system comprising: atransmitter configured to transmit power in a wireless manner; and areceiver configured to receive power from the transmitter in a wirelessmanner, wherein the transmitter comprises: a power transfer unitconfigured to transmit power to the receiver in the wireless manner; acircuit unit having a plurality of capacitors electrically connected tothe power transfer unit, and configured to support each of a pluralityof frequencies by changing the electric connection of the capacitors;and a controller configured to detect a communication standard which thewireless power receiver complies with, and control the electricconnection of the capacitors such that the circuit unit operates at afrequency corresponding to the detected communication standard.
 18. Thesystem of claim 17, wherein the power transfer unit is configured as aWPC-compliant A13 coil, and wherein the controller decides the number ofcapacitors to be included in a resonant circuit compliant with thecommunication standard which the receiver complies with.
 19. The systemof claim 18, further comprising a switch connected to at least part ofthe plurality of capacitors, and wherein the controller decide acapacitor to be used in the resonant circuit using the switch.
 20. Thesystem of claim 17, wherein the controller generates signals complyingwith different communication standards in a sequential manner so as todetect the standard that the receiver supports.